For testing purposes is nice to have a quick way of creating IIO devices.
This patch series introduces support for creating IIO devices via configs
(patch 1), allowing users to register "device types". For the moment we
support "dummy" device type (patch 2).
Patch 3 introduces configfs entries documentation for easier review.
Changes since v1:
* dropped the RFC tag
* fix coding style issues as per Jonathan suggestion
* fix configfs path in Documentation as per Lars observation (patch 3)
* allocate memory for indio_dev->name (patch 1)
* make iio_simple_dummy depend on SW_DEVICE config option in order to avoid
compilation errors reported by kbuild robot.
Daniel Baluta (3):
iio: Add support for creating IIO devices via configfs
iio: dummy: Convert IIO dummy to configfs
Documentation: iio: Add IIO software devices docs
Documentation/ABI/testing/configfs-iio | 13 +++
drivers/iio/Kconfig | 8 ++
drivers/iio/Makefile | 1 +
drivers/iio/dummy/Kconfig | 1 +
drivers/iio/dummy/iio_simple_dummy.c | 102 +++++++-----------
drivers/iio/industrialio-sw-device.c | 182 +++++++++++++++++++++++++++++++++
include/linux/iio/sw_device.h | 70 +++++++++++++
7 files changed, 312 insertions(+), 65 deletions(-)
create mode 100644 drivers/iio/industrialio-sw-device.c
create mode 100644 include/linux/iio/sw_device.h
--
2.5.0
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 <[email protected]>
---
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 <[email protected]>");
+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
Signed-off-by: Daniel Baluta <[email protected]>
---
Documentation/ABI/testing/configfs-iio | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/Documentation/ABI/testing/configfs-iio b/Documentation/ABI/testing/configfs-iio
index 2483756..aebda53 100644
--- a/Documentation/ABI/testing/configfs-iio
+++ b/Documentation/ABI/testing/configfs-iio
@@ -19,3 +19,16 @@ KernelVersion: 4.4
Description:
High resolution timers directory. Creating a directory here
will result in creating a hrtimer trigger in the IIO subsystem.
+
+What: /config/iio/devices
+Date: April 2016
+KernelVersion: 4.7
+Description:
+ Industrial IO software devices directory.
+
+What: /config/iio/devices/dummy
+Date: April 2016
+KernelVersion: 4.7
+Description:
+ Dummy IIO devices directory. Creating a directory here will result
+ in creating a dummy IIO device in the IIO subystem.
--
2.5.0
We register a new device type named "dummy", this will create a
configfs entry under:
* /config/iio/devices/dummy.
Creating dummy devices is now as simple as:
$ mkdir /config/iio/devices/dummy/my_dummy_device
Signed-off-by: Daniel Baluta <[email protected]>
---
drivers/iio/dummy/Kconfig | 1 +
drivers/iio/dummy/iio_simple_dummy.c | 102 +++++++++++++----------------------
2 files changed, 38 insertions(+), 65 deletions(-)
diff --git a/drivers/iio/dummy/Kconfig b/drivers/iio/dummy/Kconfig
index 71805ce..aa5824d 100644
--- a/drivers/iio/dummy/Kconfig
+++ b/drivers/iio/dummy/Kconfig
@@ -10,6 +10,7 @@ config IIO_DUMMY_EVGEN
config IIO_SIMPLE_DUMMY
tristate "An example driver with no hardware requirements"
+ depends on IIO_SW_DEVICE
help
Driver intended mainly as documentation for how to write
a driver. May also be useful for testing userspace code
diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c
index 43fe4ba..ad3410e 100644
--- a/drivers/iio/dummy/iio_simple_dummy.c
+++ b/drivers/iio/dummy/iio_simple_dummy.c
@@ -17,26 +17,18 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/string.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/buffer.h>
+#include <linux/iio/sw_device.h>
#include "iio_simple_dummy.h"
-/*
- * A few elements needed to fake a bus for this driver
- * Note instances parameter controls how many of these
- * dummy devices are registered.
- */
-static unsigned instances = 1;
-module_param(instances, uint, 0);
-
-/* Pointer array used to fake bus elements */
-static struct iio_dev **iio_dummy_devs;
-
-/* Fake a name for the part number, usually obtained from the id table */
-static const char *iio_dummy_part_number = "iio_dummy_part_no";
+static struct config_item_type iio_dummy_type = {
+ .ct_owner = THIS_MODULE,
+};
/**
* struct iio_dummy_accel_calibscale - realworld to register mapping
@@ -572,12 +564,18 @@ static int iio_dummy_init_device(struct iio_dev *indio_dev)
* const struct i2c_device_id *id)
* SPI: iio_dummy_probe(struct spi_device *spi)
*/
-static int iio_dummy_probe(int index)
+static struct iio_sw_device *iio_dummy_probe(const char *name)
{
int ret;
struct iio_dev *indio_dev;
struct iio_dummy_state *st;
+ struct iio_sw_device *swd;
+ swd = kzalloc(sizeof(*swd), GFP_KERNEL);
+ if (!swd) {
+ ret = -ENOMEM;
+ goto error_kzalloc;
+ }
/*
* Allocate an IIO device.
*
@@ -608,7 +606,7 @@ static int iio_dummy_probe(int index)
* i2c_set_clientdata(client, indio_dev);
* spi_set_drvdata(spi, indio_dev);
*/
- iio_dummy_devs[index] = indio_dev;
+ swd->device = indio_dev;
/*
* Set the device name.
@@ -619,7 +617,7 @@ static int iio_dummy_probe(int index)
* indio_dev->name = id->name;
* indio_dev->name = spi_get_device_id(spi)->name;
*/
- indio_dev->name = iio_dummy_part_number;
+ indio_dev->name = kstrdup(name, GFP_KERNEL);
/* Provide description of available channels */
indio_dev->channels = iio_dummy_channels;
@@ -646,7 +644,9 @@ static int iio_dummy_probe(int index)
if (ret < 0)
goto error_unconfigure_buffer;
- return 0;
+ iio_swd_group_init_type_name(swd, name, &iio_dummy_type);
+
+ return swd;
error_unconfigure_buffer:
iio_simple_dummy_unconfigure_buffer(indio_dev);
error_unregister_events:
@@ -654,16 +654,18 @@ error_unregister_events:
error_free_device:
iio_device_free(indio_dev);
error_ret:
- return ret;
+ kfree(swd);
+error_kzalloc:
+ return ERR_PTR(ret);
}
/**
* iio_dummy_remove() - device instance removal function
- * @index: device index.
+ * @swd: pointer to software IIO device abstraction
*
* Parameters follow those of iio_dummy_probe for buses.
*/
-static void iio_dummy_remove(int index)
+static int iio_dummy_remove(struct iio_sw_device *swd)
{
/*
* Get a pointer to the device instance iio_dev structure
@@ -671,7 +673,7 @@ static void iio_dummy_remove(int index)
* struct iio_dev *indio_dev = i2c_get_clientdata(client);
* struct iio_dev *indio_dev = spi_get_drvdata(spi);
*/
- struct iio_dev *indio_dev = iio_dummy_devs[index];
+ struct iio_dev *indio_dev = swd->device;
/* Unregister the device */
iio_device_unregister(indio_dev);
@@ -684,11 +686,13 @@ static void iio_dummy_remove(int index)
iio_simple_dummy_events_unregister(indio_dev);
/* Free all structures */
+ kfree(indio_dev->name);
iio_device_free(indio_dev);
-}
+ return 0;
+}
/**
- * iio_dummy_init() - device driver registration
+ * module_iio_sw_device_driver() - device driver registration
*
* Varies depending on bus type of the device. As there is no device
* here, call probe directly. For information on device registration
@@ -697,50 +701,18 @@ static void iio_dummy_remove(int index)
* spi:
* Documentation/spi/spi-summary
*/
-static __init int iio_dummy_init(void)
-{
- int i, ret;
-
- if (instances > 10) {
- instances = 1;
- return -EINVAL;
- }
-
- /* Fake a bus */
- iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs),
- GFP_KERNEL);
- /* Here we have no actual device so call probe */
- for (i = 0; i < instances; i++) {
- ret = iio_dummy_probe(i);
- if (ret < 0)
- goto error_remove_devs;
- }
- return 0;
-
-error_remove_devs:
- while (i--)
- iio_dummy_remove(i);
-
- kfree(iio_dummy_devs);
- return ret;
-}
-module_init(iio_dummy_init);
+static const struct iio_sw_device_ops iio_dummy_device_ops = {
+ .probe = iio_dummy_probe,
+ .remove = iio_dummy_remove,
+};
-/**
- * iio_dummy_exit() - device driver removal
- *
- * Varies depending on bus type of the device.
- * As there is no device here, call remove directly.
- */
-static __exit void iio_dummy_exit(void)
-{
- int i;
+static struct iio_sw_device_type iio_dummy_device = {
+ .name = "dummy",
+ .owner = THIS_MODULE,
+ .ops = &iio_dummy_device_ops,
+};
- for (i = 0; i < instances; i++)
- iio_dummy_remove(i);
- kfree(iio_dummy_devs);
-}
-module_exit(iio_dummy_exit);
+module_iio_sw_device_driver(iio_dummy_device);
MODULE_AUTHOR("Jonathan Cameron <[email protected]>");
MODULE_DESCRIPTION("IIO dummy driver");
--
2.5.0