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
214
215
216
217
218
219
220
221
222
223
224
225
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2011 Analog Devices Inc.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/irq_work.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
struct iio_sysfs_trig {
struct iio_trigger *trig;
struct irq_work work;
int id;
struct list_head l;
};
static LIST_HEAD(iio_sysfs_trig_list);
static DEFINE_MUTEX(iio_sysfs_trig_list_mut);
static int iio_sysfs_trigger_probe(int id);
static ssize_t iio_sysfs_trig_add(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
unsigned long input;
ret = kstrtoul(buf, 10, &input);
if (ret)
return ret;
ret = iio_sysfs_trigger_probe(input);
if (ret)
return ret;
return len;
}
static DEVICE_ATTR(add_trigger, S_IWUSR, NULL, &iio_sysfs_trig_add);
static int iio_sysfs_trigger_remove(int id);
static ssize_t iio_sysfs_trig_remove(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
unsigned long input;
ret = kstrtoul(buf, 10, &input);
if (ret)
return ret;
ret = iio_sysfs_trigger_remove(input);
if (ret)
return ret;
return len;
}
static DEVICE_ATTR(remove_trigger, S_IWUSR, NULL, &iio_sysfs_trig_remove);
static struct attribute *iio_sysfs_trig_attrs[] = {
&dev_attr_add_trigger.attr,
&dev_attr_remove_trigger.attr,
NULL,
};
static const struct attribute_group iio_sysfs_trig_group = {
.attrs = iio_sysfs_trig_attrs,
};
static const struct attribute_group *iio_sysfs_trig_groups[] = {
&iio_sysfs_trig_group,
NULL
};
/* Nothing to actually do upon release */
static void iio_trigger_sysfs_release(struct device *dev)
{
}
static struct device iio_sysfs_trig_dev = {
.bus = &iio_bus_type,
.groups = iio_sysfs_trig_groups,
.release = &iio_trigger_sysfs_release,
};
static void iio_sysfs_trigger_work(struct irq_work *work)
{
struct iio_sysfs_trig *trig = container_of(work, struct iio_sysfs_trig,
work);
iio_trigger_poll(trig->trig);
}
static ssize_t iio_sysfs_trigger_poll(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct iio_trigger *trig = to_iio_trigger(dev);
struct iio_sysfs_trig *sysfs_trig = iio_trigger_get_drvdata(trig);
irq_work_queue(&sysfs_trig->work);
return count;
}
static DEVICE_ATTR(trigger_now, S_IWUSR, NULL, iio_sysfs_trigger_poll);
static struct attribute *iio_sysfs_trigger_attrs[] = {
&dev_attr_trigger_now.attr,
NULL,
};
static const struct attribute_group iio_sysfs_trigger_attr_group = {
.attrs = iio_sysfs_trigger_attrs,
};
static const struct attribute_group *iio_sysfs_trigger_attr_groups[] = {
&iio_sysfs_trigger_attr_group,
NULL
};
static int iio_sysfs_trigger_probe(int id)
{
struct iio_sysfs_trig *t;
int ret;
bool foundit = false;
mutex_lock(&iio_sysfs_trig_list_mut);
list_for_each_entry(t, &iio_sysfs_trig_list, l)
if (id == t->id) {
foundit = true;
break;
}
if (foundit) {
ret = -EINVAL;
goto err_unlock;
}
t = kmalloc(sizeof(*t), GFP_KERNEL);
if (t == NULL) {
ret = -ENOMEM;
goto err_unlock;
}
t->id = id;
t->trig = iio_trigger_alloc(&iio_sysfs_trig_dev, "sysfstrig%d", id);
if (!t->trig) {
ret = -ENOMEM;
goto err_free_sys_trig;
}
t->trig->dev.groups = iio_sysfs_trigger_attr_groups;
iio_trigger_set_drvdata(t->trig, t);
t->work = IRQ_WORK_INIT_HARD(iio_sysfs_trigger_work);
ret = iio_trigger_register(t->trig);
if (ret)
goto err_free_trig;
list_add(&t->l, &iio_sysfs_trig_list);
__module_get(THIS_MODULE);
mutex_unlock(&iio_sysfs_trig_list_mut);
return 0;
err_free_trig:
iio_trigger_free(t->trig);
err_free_sys_trig:
kfree(t);
err_unlock:
mutex_unlock(&iio_sysfs_trig_list_mut);
return ret;
}
static int iio_sysfs_trigger_remove(int id)
{
struct iio_sysfs_trig *t = NULL, *iter;
mutex_lock(&iio_sysfs_trig_list_mut);
list_for_each_entry(iter, &iio_sysfs_trig_list, l)
if (id == iter->id) {
t = iter;
break;
}
if (!t) {
mutex_unlock(&iio_sysfs_trig_list_mut);
return -EINVAL;
}
iio_trigger_unregister(t->trig);
irq_work_sync(&t->work);
iio_trigger_free(t->trig);
list_del(&t->l);
kfree(t);
module_put(THIS_MODULE);
mutex_unlock(&iio_sysfs_trig_list_mut);
return 0;
}
static int __init iio_sysfs_trig_init(void)
{
int ret;
device_initialize(&iio_sysfs_trig_dev);
dev_set_name(&iio_sysfs_trig_dev, "iio_sysfs_trigger");
ret = device_add(&iio_sysfs_trig_dev);
if (ret)
put_device(&iio_sysfs_trig_dev);
return ret;
}
module_init(iio_sysfs_trig_init);
static void __exit iio_sysfs_trig_exit(void)
{
device_unregister(&iio_sysfs_trig_dev);
}
module_exit(iio_sysfs_trig_exit);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Sysfs based trigger for the iio subsystem");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:iio-trig-sysfs");
|
