1
2
3
4
5
6
7
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/kmod.h>
11#include <linux/list.h>
12#include <linux/slab.h>
13
14#include <linux/iio/sw_trigger.h>
15#include <linux/iio/configfs.h>
16#include <linux/configfs.h>
17
18static struct config_group *iio_triggers_group;
19static const struct config_item_type iio_trigger_type_group_type;
20
21static const struct config_item_type iio_triggers_group_type = {
22 .ct_owner = THIS_MODULE,
23};
24
25static LIST_HEAD(iio_trigger_types_list);
26static DEFINE_MUTEX(iio_trigger_types_lock);
27
28static
29struct iio_sw_trigger_type *__iio_find_sw_trigger_type(const char *name,
30 unsigned len)
31{
32 struct iio_sw_trigger_type *t = NULL, *iter;
33
34 list_for_each_entry(iter, &iio_trigger_types_list, list)
35 if (!strcmp(iter->name, name)) {
36 t = iter;
37 break;
38 }
39
40 return t;
41}
42
43int iio_register_sw_trigger_type(struct iio_sw_trigger_type *t)
44{
45 struct iio_sw_trigger_type *iter;
46 int ret = 0;
47
48 mutex_lock(&iio_trigger_types_lock);
49 iter = __iio_find_sw_trigger_type(t->name, strlen(t->name));
50 if (iter)
51 ret = -EBUSY;
52 else
53 list_add_tail(&t->list, &iio_trigger_types_list);
54 mutex_unlock(&iio_trigger_types_lock);
55
56 if (ret)
57 return ret;
58
59 t->group = configfs_register_default_group(iio_triggers_group, t->name,
60 &iio_trigger_type_group_type);
61 if (IS_ERR(t->group))
62 ret = PTR_ERR(t->group);
63
64 return ret;
65}
66EXPORT_SYMBOL(iio_register_sw_trigger_type);
67
68void iio_unregister_sw_trigger_type(struct iio_sw_trigger_type *t)
69{
70 struct iio_sw_trigger_type *iter;
71
72 mutex_lock(&iio_trigger_types_lock);
73 iter = __iio_find_sw_trigger_type(t->name, strlen(t->name));
74 if (iter)
75 list_del(&t->list);
76 mutex_unlock(&iio_trigger_types_lock);
77
78 configfs_unregister_default_group(t->group);
79}
80EXPORT_SYMBOL(iio_unregister_sw_trigger_type);
81
82static
83struct iio_sw_trigger_type *iio_get_sw_trigger_type(const char *name)
84{
85 struct iio_sw_trigger_type *t;
86
87 mutex_lock(&iio_trigger_types_lock);
88 t = __iio_find_sw_trigger_type(name, strlen(name));
89 if (t && !try_module_get(t->owner))
90 t = NULL;
91 mutex_unlock(&iio_trigger_types_lock);
92
93 return t;
94}
95
96struct iio_sw_trigger *iio_sw_trigger_create(const char *type, const char *name)
97{
98 struct iio_sw_trigger *t;
99 struct iio_sw_trigger_type *tt;
100
101 tt = iio_get_sw_trigger_type(type);
102 if (!tt) {
103 pr_err("Invalid trigger type: %s\n", type);
104 return ERR_PTR(-EINVAL);
105 }
106 t = tt->ops->probe(name);
107 if (IS_ERR(t))
108 goto out_module_put;
109
110 t->trigger_type = tt;
111
112 return t;
113out_module_put:
114 module_put(tt->owner);
115 return t;
116}
117EXPORT_SYMBOL(iio_sw_trigger_create);
118
119void iio_sw_trigger_destroy(struct iio_sw_trigger *t)
120{
121 struct iio_sw_trigger_type *tt = t->trigger_type;
122
123 tt->ops->remove(t);
124 module_put(tt->owner);
125}
126EXPORT_SYMBOL(iio_sw_trigger_destroy);
127
128static struct config_group *trigger_make_group(struct config_group *group,
129 const char *name)
130{
131 struct iio_sw_trigger *t;
132
133 t = iio_sw_trigger_create(group->cg_item.ci_name, name);
134 if (IS_ERR(t))
135 return ERR_CAST(t);
136
137 config_item_set_name(&t->group.cg_item, "%s", name);
138
139 return &t->group;
140}
141
142static void trigger_drop_group(struct config_group *group,
143 struct config_item *item)
144{
145 struct iio_sw_trigger *t = to_iio_sw_trigger(item);
146
147 iio_sw_trigger_destroy(t);
148 config_item_put(item);
149}
150
151static struct configfs_group_operations trigger_ops = {
152 .make_group = &trigger_make_group,
153 .drop_item = &trigger_drop_group,
154};
155
156static const struct config_item_type iio_trigger_type_group_type = {
157 .ct_group_ops = &trigger_ops,
158 .ct_owner = THIS_MODULE,
159};
160
161static int __init iio_sw_trigger_init(void)
162{
163 iio_triggers_group =
164 configfs_register_default_group(&iio_configfs_subsys.su_group,
165 "triggers",
166 &iio_triggers_group_type);
167 return PTR_ERR_OR_ZERO(iio_triggers_group);
168}
169module_init(iio_sw_trigger_init);
170
171static void __exit iio_sw_trigger_exit(void)
172{
173 configfs_unregister_default_group(iio_triggers_group);
174}
175module_exit(iio_sw_trigger_exit);
176
177MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
178MODULE_DESCRIPTION("Industrial I/O software triggers support");
179MODULE_LICENSE("GPL v2");
180
