diff options
Diffstat (limited to 'drivers/iio/industrialio-sw-trigger.c')
| -rw-r--r-- | drivers/iio/industrialio-sw-trigger.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-sw-trigger.c b/drivers/iio/industrialio-sw-trigger.c new file mode 100644 index 000000000000..8d24fb159cc9 --- /dev/null +++ b/drivers/iio/industrialio-sw-trigger.c @@ -0,0 +1,182 @@ +/* + * The Industrial I/O core, software trigger functions + * + * Copyright (c) 2015 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#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 struct config_item_type iio_trigger_type_group_type; + +static 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)) + 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 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"); |