diff options
Diffstat (limited to 'drivers/iio/industrialio-sw-device.c')
| -rw-r--r-- | drivers/iio/industrialio-sw-device.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-sw-device.c b/drivers/iio/industrialio-sw-device.c new file mode 100644 index 000000000000..81b49cfca452 --- /dev/null +++ b/drivers/iio/industrialio-sw-device.c @@ -0,0 +1,182 @@ +/* + * 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"); |