/* * The Industrial I/O core, software IIO devices functions * * Copyright (c) 2016 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_device.h> #include <linux/iio/configfs.h> #include <linux/configfs.h> static struct config_group *iio_devices_group; static struct config_item_type iio_device_type_group_type; static struct config_item_type iio_devices_group_type = { .ct_owner = THIS_MODULE, }; static LIST_HEAD(iio_device_types_list); static DEFINE_MUTEX(iio_device_types_lock); static struct iio_sw_device_type *__iio_find_sw_device_type(const char *name, unsigned len) { struct iio_sw_device_type *d = NULL, *iter; list_for_each_entry(iter, &iio_device_types_list, list) if (!strcmp(iter->name, name)) { d = iter; break; } return d; } int iio_register_sw_device_type(struct iio_sw_device_type *d) { struct iio_sw_device_type *iter; int ret = 0; mutex_lock(&iio_device_types_lock); iter = __iio_find_sw_device_type(d->name, strlen(d->name)); if (iter) ret = -EBUSY; else list_add_tail(&d->list, &iio_device_types_list); mutex_unlock(&iio_device_types_lock); if (ret) return ret; d->group = configfs_register_default_group(iio_devices_group, d->name, &iio_device_type_group_type); if (IS_ERR(d->group)) ret = PTR_ERR(d->group); return ret; } EXPORT_SYMBOL(iio_register_sw_device_type); void iio_unregister_sw_device_type(struct iio_sw_device_type *dt) { struct iio_sw_device_type *iter; mutex_lock(&iio_device_types_lock); iter = __iio_find_sw_device_type(dt->name, strlen(dt->name)); if (iter) list_del(&dt->list); mutex_unlock(&iio_device_types_lock); configfs_unregister_default_group(dt->group); } EXPORT_SYMBOL(iio_unregister_sw_device_type); static struct iio_sw_device_type *iio_get_sw_device_type(const char *name) { struct iio_sw_device_type *dt; mutex_lock(&iio_device_types_lock); dt = __iio_find_sw_device_type(name, strlen(name)); if (dt && !try_module_get(dt->owner)) dt = NULL; mutex_unlock(&iio_device_types_lock); return dt; } struct iio_sw_device *iio_sw_device_create(const char *type, const char *name) { struct iio_sw_device *d; struct iio_sw_device_type *dt; dt = iio_get_sw_device_type(type); if (!dt) { pr_err("Invalid device type: %s\n", type); return ERR_PTR(-EINVAL); } d = dt->ops->probe(name); if (IS_ERR(d)) goto out_module_put; d->device_type = dt; return d; out_module_put: module_put(dt->owner); return d; } EXPORT_SYMBOL(iio_sw_device_create); void iio_sw_device_destroy(struct iio_sw_device *d) { struct iio_sw_device_type *dt = d->device_type; dt->ops->remove(d); module_put(dt->owner); } EXPORT_SYMBOL(iio_sw_device_destroy); static struct config_group *device_make_group(struct config_group *group, const char *name) { struct iio_sw_device *d; d = iio_sw_device_create(group->cg_item.ci_name, name); if (IS_ERR(d)) return ERR_CAST(d); config_item_set_name(&d->group.cg_item, "%s", name); return &d->group; } static void device_drop_group(struct config_group *group, struct config_item *item) { struct iio_sw_device *d = to_iio_sw_device(item); iio_sw_device_destroy(d); config_item_put(item); } static struct configfs_group_operations device_ops = { .make_group = &device_make_group, .drop_item = &device_drop_group, }; static struct config_item_type iio_device_type_group_type = { .ct_group_ops = &device_ops, .ct_owner = THIS_MODULE, }; static int __init iio_sw_device_init(void) { iio_devices_group = configfs_register_default_group(&iio_configfs_subsys.su_group, "devices", &iio_devices_group_type); return PTR_ERR_OR_ZERO(iio_devices_group); } module_init(iio_sw_device_init); static void __exit iio_sw_device_exit(void) { configfs_unregister_default_group(iio_devices_group); } module_exit(iio_sw_device_exit); MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>"); MODULE_DESCRIPTION("Industrial I/O software devices support"); MODULE_LICENSE("GPL v2");