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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * The Industrial I/O core, software IIO devices functions4 *5 * Copyright (c) 2016 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_device.h>15#include <linux/iio/configfs.h>16#include <linux/configfs.h>17 18static struct config_group *iio_devices_group;19static const struct config_item_type iio_device_type_group_type;20 21static const struct config_item_type iio_devices_group_type = {22 .ct_owner = THIS_MODULE,23};24 25static LIST_HEAD(iio_device_types_list);26static DEFINE_MUTEX(iio_device_types_lock);27 28static29struct iio_sw_device_type *__iio_find_sw_device_type(const char *name,30 unsigned int len)31{32 struct iio_sw_device_type *d = NULL, *iter;33 34 list_for_each_entry(iter, &iio_device_types_list, list)35 if (!strcmp(iter->name, name)) {36 d = iter;37 break;38 }39 40 return d;41}42 43int iio_register_sw_device_type(struct iio_sw_device_type *d)44{45 struct iio_sw_device_type *iter;46 int ret = 0;47 48 mutex_lock(&iio_device_types_lock);49 iter = __iio_find_sw_device_type(d->name, strlen(d->name));50 if (iter)51 ret = -EBUSY;52 else53 list_add_tail(&d->list, &iio_device_types_list);54 mutex_unlock(&iio_device_types_lock);55 56 if (ret)57 return ret;58 59 d->group = configfs_register_default_group(iio_devices_group, d->name,60 &iio_device_type_group_type);61 if (IS_ERR(d->group))62 ret = PTR_ERR(d->group);63 64 return ret;65}66EXPORT_SYMBOL(iio_register_sw_device_type);67 68void iio_unregister_sw_device_type(struct iio_sw_device_type *dt)69{70 struct iio_sw_device_type *iter;71 72 mutex_lock(&iio_device_types_lock);73 iter = __iio_find_sw_device_type(dt->name, strlen(dt->name));74 if (iter)75 list_del(&dt->list);76 mutex_unlock(&iio_device_types_lock);77 78 configfs_unregister_default_group(dt->group);79}80EXPORT_SYMBOL(iio_unregister_sw_device_type);81 82static83struct iio_sw_device_type *iio_get_sw_device_type(const char *name)84{85 struct iio_sw_device_type *dt;86 87 mutex_lock(&iio_device_types_lock);88 dt = __iio_find_sw_device_type(name, strlen(name));89 if (dt && !try_module_get(dt->owner))90 dt = NULL;91 mutex_unlock(&iio_device_types_lock);92 93 return dt;94}95 96struct iio_sw_device *iio_sw_device_create(const char *type, const char *name)97{98 struct iio_sw_device *d;99 struct iio_sw_device_type *dt;100 101 dt = iio_get_sw_device_type(type);102 if (!dt) {103 pr_err("Invalid device type: %s\n", type);104 return ERR_PTR(-EINVAL);105 }106 d = dt->ops->probe(name);107 if (IS_ERR(d))108 goto out_module_put;109 110 d->device_type = dt;111 112 return d;113out_module_put:114 module_put(dt->owner);115 return d;116}117EXPORT_SYMBOL(iio_sw_device_create);118 119void iio_sw_device_destroy(struct iio_sw_device *d)120{121 struct iio_sw_device_type *dt = d->device_type;122 123 dt->ops->remove(d);124 module_put(dt->owner);125}126EXPORT_SYMBOL(iio_sw_device_destroy);127 128static struct config_group *device_make_group(struct config_group *group,129 const char *name)130{131 struct iio_sw_device *d;132 133 d = iio_sw_device_create(group->cg_item.ci_name, name);134 if (IS_ERR(d))135 return ERR_CAST(d);136 137 config_item_set_name(&d->group.cg_item, "%s", name);138 139 return &d->group;140}141 142static void device_drop_group(struct config_group *group,143 struct config_item *item)144{145 struct iio_sw_device *d = to_iio_sw_device(item);146 147 iio_sw_device_destroy(d);148 config_item_put(item);149}150 151static struct configfs_group_operations device_ops = {152 .make_group = &device_make_group,153 .drop_item = &device_drop_group,154};155 156static const struct config_item_type iio_device_type_group_type = {157 .ct_group_ops = &device_ops,158 .ct_owner = THIS_MODULE,159};160 161static int __init iio_sw_device_init(void)162{163 iio_devices_group =164 configfs_register_default_group(&iio_configfs_subsys.su_group,165 "devices",166 &iio_devices_group_type);167 return PTR_ERR_OR_ZERO(iio_devices_group);168}169module_init(iio_sw_device_init);170 171static void __exit iio_sw_device_exit(void)172{173 configfs_unregister_default_group(iio_devices_group);174}175module_exit(iio_sw_device_exit);176 177MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");178MODULE_DESCRIPTION("Industrial I/O software devices support");179MODULE_LICENSE("GPL v2");180