1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Support for polling mode for input devices.
*/
#include <linux/device.h>
#include <linux/input.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include "input-poller.h"
struct input_dev_poller {
void (*poll)(struct input_dev *dev);
unsigned int poll_interval; /* msec */
unsigned int poll_interval_max; /* msec */
unsigned int poll_interval_min; /* msec */
struct input_dev *input;
struct delayed_work work;
};
static void input_dev_poller_queue_work(struct input_dev_poller *poller)
{
unsigned long delay;
delay = msecs_to_jiffies(poller->poll_interval);
if (delay >= HZ)
delay = round_jiffies_relative(delay);
queue_delayed_work(system_freezable_wq, &poller->work, delay);
}
static void input_dev_poller_work(struct work_struct *work)
{
struct input_dev_poller *poller =
container_of(work, struct input_dev_poller, work.work);
poller->poll(poller->input);
input_dev_poller_queue_work(poller);
}
void input_dev_poller_finalize(struct input_dev_poller *poller)
{
if (!poller->poll_interval)
poller->poll_interval = 500;
if (!poller->poll_interval_max)
poller->poll_interval_max = poller->poll_interval;
}
void input_dev_poller_start(struct input_dev_poller *poller)
{
/* Only start polling if polling is enabled */
if (poller->poll_interval > 0) {
poller->poll(poller->input);
input_dev_poller_queue_work(poller);
}
}
void input_dev_poller_stop(struct input_dev_poller *poller)
{
cancel_delayed_work_sync(&poller->work);
}
int input_setup_polling(struct input_dev *dev,
void (*poll_fn)(struct input_dev *dev))
{
struct input_dev_poller *poller;
poller = kzalloc(sizeof(*poller), GFP_KERNEL);
if (!poller) {
/*
* We want to show message even though kzalloc() may have
* printed backtrace as knowing what instance of input
* device we were dealing with is helpful.
*/
dev_err(dev->dev.parent ?: &dev->dev,
"%s: unable to allocate poller structure\n", __func__);
return -ENOMEM;
}
INIT_DELAYED_WORK(&poller->work, input_dev_poller_work);
poller->input = dev;
poller->poll = poll_fn;
dev->poller = poller;
return 0;
}
EXPORT_SYMBOL(input_setup_polling);
static bool input_dev_ensure_poller(struct input_dev *dev)
{
if (!dev->poller) {
dev_err(dev->dev.parent ?: &dev->dev,
"poller structure has not been set up\n");
return false;
}
return true;
}
void input_set_poll_interval(struct input_dev *dev, unsigned int interval)
{
if (input_dev_ensure_poller(dev))
dev->poller->poll_interval = interval;
}
EXPORT_SYMBOL(input_set_poll_interval);
void input_set_min_poll_interval(struct input_dev *dev, unsigned int interval)
{
if (input_dev_ensure_poller(dev))
dev->poller->poll_interval_min = interval;
}
EXPORT_SYMBOL(input_set_min_poll_interval);
void input_set_max_poll_interval(struct input_dev *dev, unsigned int interval)
{
if (input_dev_ensure_poller(dev))
dev->poller->poll_interval_max = interval;
}
EXPORT_SYMBOL(input_set_max_poll_interval);
/* SYSFS interface */
static ssize_t input_dev_get_poll_interval(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct input_dev *input = to_input_dev(dev);
return sprintf(buf, "%d\n", input->poller->poll_interval);
}
static ssize_t input_dev_set_poll_interval(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct input_dev *input = to_input_dev(dev);
struct input_dev_poller *poller = input->poller;
unsigned int interval;
int err;
err = kstrtouint(buf, 0, &interval);
if (err)
return err;
if (interval < poller->poll_interval_min)
return -EINVAL;
if (interval > poller->poll_interval_max)
return -EINVAL;
mutex_lock(&input->mutex);
poller->poll_interval = interval;
if (input->users) {
cancel_delayed_work_sync(&poller->work);
if (poller->poll_interval > 0)
input_dev_poller_queue_work(poller);
}
mutex_unlock(&input->mutex);
return count;
}
static DEVICE_ATTR(poll, 0644,
input_dev_get_poll_interval, input_dev_set_poll_interval);
static ssize_t input_dev_get_poll_max(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct input_dev *input = to_input_dev(dev);
return sprintf(buf, "%d\n", input->poller->poll_interval_max);
}
static DEVICE_ATTR(max, 0444, input_dev_get_poll_max, NULL);
static ssize_t input_dev_get_poll_min(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct input_dev *input = to_input_dev(dev);
return sprintf(buf, "%d\n", input->poller->poll_interval_min);
}
static DEVICE_ATTR(min, 0444, input_dev_get_poll_min, NULL);
static umode_t input_poller_attrs_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct input_dev *input = to_input_dev(dev);
return input->poller ? attr->mode : 0;
}
static struct attribute *input_poller_attrs[] = {
&dev_attr_poll.attr,
&dev_attr_max.attr,
&dev_attr_min.attr,
NULL
};
struct attribute_group input_poller_attribute_group = {
.is_visible = input_poller_attrs_visible,
.attrs = input_poller_attrs,
};
|
