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-rw-r--r--drivers/iio/industrialio-sw-trigger.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-sw-trigger.c b/drivers/iio/industrialio-sw-trigger.c
new file mode 100644
index 000000000..d86a3305d
--- /dev/null
+++ b/drivers/iio/industrialio-sw-trigger.c
@@ -0,0 +1,183 @@
+// 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 int 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");