This is similar with support for creating triggers via configfs.
Devices will be hosted under:
* /config/iio/devices
We allow users to register "device types" under:
* /config/iio/devices/<device_types>/
Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
drivers/iio/Kconfig | 8 ++
drivers/iio/Makefile | 1 +
drivers/iio/industrialio-sw-device.c | 182 +++++++++++++++++++++++++++++++++++
include/linux/iio/sw_device.h | 70 ++++++++++++++
4 files changed, 261 insertions(+)
create mode 100644 drivers/iio/industrialio-sw-device.c
create mode 100644 include/linux/iio/sw_device.h
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 505e921..6743b18 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -46,6 +46,14 @@ config IIO_CONSUMERS_PER_TRIGGER
This value controls the maximum number of consumers that a
given trigger may handle. Default is 2.
+config IIO_SW_DEVICE
+ tristate "Enable software IIO device support"
+ select IIO_CONFIGFS
+ help
+ Provides IIO core support for software devices. A software
+ device can be created via configfs or directly by a driver
+ using the API provided.
+
config IIO_SW_TRIGGER
tristate "Enable software triggers support"
select IIO_CONFIGFS
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 20f6490..87e4c43 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -8,6 +8,7 @@ industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
obj-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o
+obj-$(CONFIG_IIO_SW_DEVICE) += industrialio-sw-device.o
obj-$(CONFIG_IIO_SW_TRIGGER) += industrialio-sw-trigger.o
obj-$(CONFIG_IIO_TRIGGERED_EVENT) += industrialio-triggered-event.o
diff --git a/drivers/iio/industrialio-sw-device.c b/drivers/iio/industrialio-sw-device.c
new file mode 100644
index 0000000..81b49cf
--- /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@xxxxxxxxx>");
+MODULE_DESCRIPTION("Industrial I/O software devices support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/iio/sw_device.h b/include/linux/iio/sw_device.h
new file mode 100644
index 0000000..23ca415
--- /dev/null
+++ b/include/linux/iio/sw_device.h
@@ -0,0 +1,70 @@
+/*
+ * Industrial I/O software device interface
+ *
+ * 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.
+ */
+
+#ifndef __IIO_SW_DEVICE
+#define __IIO_SW_DEVICE
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/configfs.h>
+
+#define module_iio_sw_device_driver(__iio_sw_device_type) \
+ module_driver(__iio_sw_device_type, iio_register_sw_device_type, \
+ iio_unregister_sw_device_type)
+
+struct iio_sw_device_ops;
+
+struct iio_sw_device_type {
+ const char *name;
+ struct module *owner;
+ const struct iio_sw_device_ops *ops;
+ struct list_head list;
+ struct config_group *group;
+};
+
+struct iio_sw_device {
+ struct iio_dev *device;
+ struct iio_sw_device_type *device_type;
+ struct config_group group;
+};
+
+struct iio_sw_device_ops {
+ struct iio_sw_device* (*probe)(const char *);
+ int (*remove)(struct iio_sw_device *);
+};
+
+static inline
+struct iio_sw_device *to_iio_sw_device(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct iio_sw_device,
+ group);
+}
+
+int iio_register_sw_device_type(struct iio_sw_device_type *dt);
+void iio_unregister_sw_device_type(struct iio_sw_device_type *dt);
+
+struct iio_sw_device *iio_sw_device_create(const char *, const char *);
+void iio_sw_device_destroy(struct iio_sw_device *);
+
+int iio_sw_device_type_configfs_register(struct iio_sw_device_type *dt);
+void iio_sw_device_type_configfs_unregister(struct iio_sw_device_type *dt);
+
+static inline
+void iio_swd_group_init_type_name(struct iio_sw_device *d,
+ const char *name,
+ struct config_item_type *type)
+{
+#ifdef CONFIG_CONFIGFS_FS
+ config_group_init_type_name(&d->group, name, type);
+#endif
+}
+
+#endif /* __IIO_SW_DEVICE */
--
2.5.0
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