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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * The Industrial I/O core, software trigger functions4 *5 * Copyright (c) 2015 Intel Corporation6 */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 28static29struct iio_sw_trigger_type *__iio_find_sw_trigger_type(const char *name,30 unsigned int 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 else53 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 mutex_lock(&iio_trigger_types_lock);63 list_del(&t->list);64 mutex_unlock(&iio_trigger_types_lock);65 ret = PTR_ERR(t->group);66 }67 68 return ret;69}70EXPORT_SYMBOL(iio_register_sw_trigger_type);71 72void iio_unregister_sw_trigger_type(struct iio_sw_trigger_type *t)73{74 struct iio_sw_trigger_type *iter;75 76 mutex_lock(&iio_trigger_types_lock);77 iter = __iio_find_sw_trigger_type(t->name, strlen(t->name));78 if (iter)79 list_del(&t->list);80 mutex_unlock(&iio_trigger_types_lock);81 82 configfs_unregister_default_group(t->group);83}84EXPORT_SYMBOL(iio_unregister_sw_trigger_type);85 86static87struct iio_sw_trigger_type *iio_get_sw_trigger_type(const char *name)88{89 struct iio_sw_trigger_type *t;90 91 mutex_lock(&iio_trigger_types_lock);92 t = __iio_find_sw_trigger_type(name, strlen(name));93 if (t && !try_module_get(t->owner))94 t = NULL;95 mutex_unlock(&iio_trigger_types_lock);96 97 return t;98}99 100struct iio_sw_trigger *iio_sw_trigger_create(const char *type, const char *name)101{102 struct iio_sw_trigger *t;103 struct iio_sw_trigger_type *tt;104 105 tt = iio_get_sw_trigger_type(type);106 if (!tt) {107 pr_err("Invalid trigger type: %s\n", type);108 return ERR_PTR(-EINVAL);109 }110 t = tt->ops->probe(name);111 if (IS_ERR(t))112 goto out_module_put;113 114 t->trigger_type = tt;115 116 return t;117out_module_put:118 module_put(tt->owner);119 return t;120}121EXPORT_SYMBOL(iio_sw_trigger_create);122 123void iio_sw_trigger_destroy(struct iio_sw_trigger *t)124{125 struct iio_sw_trigger_type *tt = t->trigger_type;126 127 tt->ops->remove(t);128 module_put(tt->owner);129}130EXPORT_SYMBOL(iio_sw_trigger_destroy);131 132static struct config_group *trigger_make_group(struct config_group *group,133 const char *name)134{135 struct iio_sw_trigger *t;136 137 t = iio_sw_trigger_create(group->cg_item.ci_name, name);138 if (IS_ERR(t))139 return ERR_CAST(t);140 141 config_item_set_name(&t->group.cg_item, "%s", name);142 143 return &t->group;144}145 146static void trigger_drop_group(struct config_group *group,147 struct config_item *item)148{149 struct iio_sw_trigger *t = to_iio_sw_trigger(item);150 151 iio_sw_trigger_destroy(t);152 config_item_put(item);153}154 155static struct configfs_group_operations trigger_ops = {156 .make_group = &trigger_make_group,157 .drop_item = &trigger_drop_group,158};159 160static const struct config_item_type iio_trigger_type_group_type = {161 .ct_group_ops = &trigger_ops,162 .ct_owner = THIS_MODULE,163};164 165static int __init iio_sw_trigger_init(void)166{167 iio_triggers_group =168 configfs_register_default_group(&iio_configfs_subsys.su_group,169 "triggers",170 &iio_triggers_group_type);171 return PTR_ERR_OR_ZERO(iio_triggers_group);172}173module_init(iio_sw_trigger_init);174 175static void __exit iio_sw_trigger_exit(void)176{177 configfs_unregister_default_group(iio_triggers_group);178}179module_exit(iio_sw_trigger_exit);180 181MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");182MODULE_DESCRIPTION("Industrial I/O software triggers support");183MODULE_LICENSE("GPL v2");184