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 
21 static struct class *wakeup_class;
22 
23 #define wakeup_attr(_name)						\
24 static 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 }									\
31 static DEVICE_ATTR_RO(_name)
32 
33 wakeup_attr(active_count);
34 wakeup_attr(event_count);
35 wakeup_attr(wakeup_count);
36 wakeup_attr(expire_count);
37 
38 static 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 sysfs_emit(buf, "%lld\n", ktime_to_ms(active_time));
46 }
47 static DEVICE_ATTR_RO(active_time_ms);
48 
49 static 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 
61 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(total_time));
62 }
63 static DEVICE_ATTR_RO(total_time_ms);
64 
65 static ssize_t max_time_ms_show(struct device *dev,
66 				struct device_attribute *attr, char *buf)
67 {
68 	struct wakeup_source *ws = dev_get_drvdata(dev);
69 	ktime_t active_time;
70 	ktime_t max_time = ws->max_time;
71 
72 	if (ws->active) {
73 		active_time = ktime_sub(ktime_get(), ws->last_time);
74 		if (active_time > max_time)
75 			max_time = active_time;
76 	}
77 
78 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(max_time));
79 }
80 static DEVICE_ATTR_RO(max_time_ms);
81 
82 static ssize_t last_change_ms_show(struct device *dev,
83 				   struct device_attribute *attr, char *buf)
84 {
85 	struct wakeup_source *ws = dev_get_drvdata(dev);
86 
87 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(ws->last_time));
88 }
89 static DEVICE_ATTR_RO(last_change_ms);
90 
91 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
92 			 char *buf)
93 {
94 	struct wakeup_source *ws = dev_get_drvdata(dev);
95 
96 	return sysfs_emit(buf, "%s\n", ws->name);
97 }
98 static DEVICE_ATTR_RO(name);
99 
100 static ssize_t prevent_suspend_time_ms_show(struct device *dev,
101 					    struct device_attribute *attr,
102 					    char *buf)
103 {
104 	struct wakeup_source *ws = dev_get_drvdata(dev);
105 	ktime_t prevent_sleep_time = ws->prevent_sleep_time;
106 
107 	if (ws->active && ws->autosleep_enabled) {
108 		prevent_sleep_time = ktime_add(prevent_sleep_time,
109 			ktime_sub(ktime_get(), ws->start_prevent_time));
110 	}
111 
112 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
113 }
114 static DEVICE_ATTR_RO(prevent_suspend_time_ms);
115 
116 static struct attribute *wakeup_source_attrs[] = {
117 	&dev_attr_name.attr,
118 	&dev_attr_active_count.attr,
119 	&dev_attr_event_count.attr,
120 	&dev_attr_wakeup_count.attr,
121 	&dev_attr_expire_count.attr,
122 	&dev_attr_active_time_ms.attr,
123 	&dev_attr_total_time_ms.attr,
124 	&dev_attr_max_time_ms.attr,
125 	&dev_attr_last_change_ms.attr,
126 	&dev_attr_prevent_suspend_time_ms.attr,
127 	NULL,
128 };
129 ATTRIBUTE_GROUPS(wakeup_source);
130 
131 static void device_create_release(struct device *dev)
132 {
133 	kfree(dev);
134 }
135 
136 static struct device *wakeup_source_device_create(struct device *parent,
137 						  struct wakeup_source *ws)
138 {
139 	struct device *dev = NULL;
140 	int retval;
141 
142 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
143 	if (!dev) {
144 		retval = -ENOMEM;
145 		goto error;
146 	}
147 
148 	device_initialize(dev);
149 	dev->devt = MKDEV(0, 0);
150 	dev->class = wakeup_class;
151 	dev->parent = parent;
152 	dev->groups = wakeup_source_groups;
153 	dev->release = device_create_release;
154 	dev_set_drvdata(dev, ws);
155 	device_set_pm_not_required(dev);
156 
157 	retval = dev_set_name(dev, "wakeup%d", ws->id);
158 	if (retval)
159 		goto error;
160 
161 	retval = device_add(dev);
162 	if (retval)
163 		goto error;
164 
165 	return dev;
166 
167 error:
168 	put_device(dev);
169 	return ERR_PTR(retval);
170 }
171 
172 /**
173  * wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.
174  * @parent: Device given wakeup source is associated with (or NULL if virtual).
175  * @ws: Wakeup source to be added in sysfs.
176  */
177 int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
178 {
179 	struct device *dev;
180 
181 	dev = wakeup_source_device_create(parent, ws);
182 	if (IS_ERR(dev))
183 		return PTR_ERR(dev);
184 	ws->dev = dev;
185 
186 	return 0;
187 }
188 
189 /**
190  * pm_wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs
191  * for a device if they're missing.
192  * @parent: Device given wakeup source is associated with
193  */
194 int pm_wakeup_source_sysfs_add(struct device *parent)
195 {
196 	if (!parent->power.wakeup || parent->power.wakeup->dev)
197 		return 0;
198 
199 	return wakeup_source_sysfs_add(parent, parent->power.wakeup);
200 }
201 
202 /**
203  * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs.
204  * @ws: Wakeup source to be removed from sysfs.
205  */
206 void wakeup_source_sysfs_remove(struct wakeup_source *ws)
207 {
208 	device_unregister(ws->dev);
209 }
210 
211 static int __init wakeup_sources_sysfs_init(void)
212 {
213 	wakeup_class = class_create("wakeup");
214 
215 	return PTR_ERR_OR_ZERO(wakeup_class);
216 }
217 postcore_initcall(wakeup_sources_sysfs_init);
218