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// SPDX-License-Identifier: GPL-2.0-only
/*
* The Industrial I/O core, software trigger functions
*
* Copyright (c) 2015 Intel Corporation
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/iio/sw_trigger.h>
#include <linux/iio/configfs.h>
#include <linux/configfs.h>
static struct config_group *iio_triggers_group;
static const struct config_item_type iio_trigger_type_group_type;
static const struct config_item_type iio_triggers_group_type = {
.ct_owner = THIS_MODULE,
};
static LIST_HEAD(iio_trigger_types_list);
static DEFINE_MUTEX(iio_trigger_types_lock);
static
struct iio_sw_trigger_type *__iio_find_sw_trigger_type(const char *name,
unsigned len)
{
struct iio_sw_trigger_type *t = NULL, *iter;
list_for_each_entry(iter, &iio_trigger_types_list, list)
if (!strcmp(iter->name, name)) {
t = iter;
break;
}
return t;
}
int iio_register_sw_trigger_type(struct iio_sw_trigger_type *t)
{
struct iio_sw_trigger_type *iter;
int ret = 0;
mutex_lock(&iio_trigger_types_lock);
iter = __iio_find_sw_trigger_type(t->name, strlen(t->name));
if (iter)
ret = -EBUSY;
else
list_add_tail(&t->list, &iio_trigger_types_list);
mutex_unlock(&iio_trigger_types_lock);
if (ret)
return ret;
t->group = configfs_register_default_group(iio_triggers_group, t->name,
&iio_trigger_type_group_type);
if (IS_ERR(t->group)) {
mutex_lock(&iio_trigger_types_lock);
list_del(&t->list);
mutex_unlock(&iio_trigger_types_lock);
ret = PTR_ERR(t->group);
}
return ret;
}
EXPORT_SYMBOL(iio_register_sw_trigger_type);
void iio_unregister_sw_trigger_type(struct iio_sw_trigger_type *t)
{
struct iio_sw_trigger_type *iter;
mutex_lock(&iio_trigger_types_lock);
iter = __iio_find_sw_trigger_type(t->name, strlen(t->name));
if (iter)
list_del(&t->list);
mutex_unlock(&iio_trigger_types_lock);
configfs_unregister_default_group(t->group);
}
EXPORT_SYMBOL(iio_unregister_sw_trigger_type);
static
struct iio_sw_trigger_type *iio_get_sw_trigger_type(const char *name)
{
struct iio_sw_trigger_type *t;
mutex_lock(&iio_trigger_types_lock);
t = __iio_find_sw_trigger_type(name, strlen(name));
if (t && !try_module_get(t->owner))
t = NULL;
mutex_unlock(&iio_trigger_types_lock);
return t;
}
struct iio_sw_trigger *iio_sw_trigger_create(const char *type, const char *name)
{
struct iio_sw_trigger *t;
struct iio_sw_trigger_type *tt;
tt = iio_get_sw_trigger_type(type);
if (!tt) {
pr_err("Invalid trigger type: %s\n", type);
return ERR_PTR(-EINVAL);
}
t = tt->ops->probe(name);
if (IS_ERR(t))
goto out_module_put;
t->trigger_type = tt;
return t;
out_module_put:
module_put(tt->owner);
return t;
}
EXPORT_SYMBOL(iio_sw_trigger_create);
void iio_sw_trigger_destroy(struct iio_sw_trigger *t)
{
struct iio_sw_trigger_type *tt = t->trigger_type;
tt->ops->remove(t);
module_put(tt->owner);
}
EXPORT_SYMBOL(iio_sw_trigger_destroy);
static struct config_group *trigger_make_group(struct config_group *group,
const char *name)
{
struct iio_sw_trigger *t;
t = iio_sw_trigger_create(group->cg_item.ci_name, name);
if (IS_ERR(t))
return ERR_CAST(t);
config_item_set_name(&t->group.cg_item, "%s", name);
return &t->group;
}
static void trigger_drop_group(struct config_group *group,
struct config_item *item)
{
struct iio_sw_trigger *t = to_iio_sw_trigger(item);
iio_sw_trigger_destroy(t);
config_item_put(item);
}
static struct configfs_group_operations trigger_ops = {
.make_group = &trigger_make_group,
.drop_item = &trigger_drop_group,
};
static const struct config_item_type iio_trigger_type_group_type = {
.ct_group_ops = &trigger_ops,
.ct_owner = THIS_MODULE,
};
static int __init iio_sw_trigger_init(void)
{
iio_triggers_group =
configfs_register_default_group(&iio_configfs_subsys.su_group,
"triggers",
&iio_triggers_group_type);
return PTR_ERR_OR_ZERO(iio_triggers_group);
}
module_init(iio_sw_trigger_init);
static void __exit iio_sw_trigger_exit(void)
{
configfs_unregister_default_group(iio_triggers_group);
}
module_exit(iio_sw_trigger_exit);
MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
MODULE_DESCRIPTION("Industrial I/O software triggers support");
MODULE_LICENSE("GPL v2");
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