Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx> --- Documentation/ABI/testing/configfs-iio | 20 ++++++++++++ Documentation/iio/iio_configfs.txt | 57 ++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) create mode 100644 Documentation/ABI/testing/configfs-iio create mode 100644 Documentation/iio/iio_configfs.txt diff --git a/Documentation/ABI/testing/configfs-iio b/Documentation/ABI/testing/configfs-iio new file mode 100644 index 0000000..1fd7cf4 --- /dev/null +++ b/Documentation/ABI/testing/configfs-iio @@ -0,0 +1,20 @@ +What: /config/iio +Date: May 2015 +KernelVersion: 4.2 +Contact: linux-iio@xxxxxxxxxxxxxxx +Description: + This represents Industrial IO configuration entry point + directory. It contains sub-groups corresponding to IIO + objects. + +What: /config/iio/triggers +Date: August 2015 +KernelVersion: 4.2 +Description: + Industrial IO software triggers directory. + +What: /config/iio/triggers/hrtimer +Date: August 2015 +KernelVersion: 4.2 +Description: + Industrial IO hrtimer based software triggers directory. diff --git a/Documentation/iio/iio_configfs.txt b/Documentation/iio/iio_configfs.txt new file mode 100644 index 0000000..7c56997 --- /dev/null +++ b/Documentation/iio/iio_configfs.txt @@ -0,0 +1,57 @@ +Industrial IIO configfs support + +1. Overview + +Configfs is a filesystem-based manager of kernel objects. IIO uses some +objects that could be easily configured using configfs (e.g.: devices, +triggers). + +See Documentation/filesystems/configfs/configfs.txt for more information +about how configfs works. + +2. Usage + +In order to use configfs support in IIO we need to select it at compile +time via CONFIG_IIO_CONFIGFS config option. + +Then, mount the configfs filesystem (usually under /config directory): + +$ mkdir /config +$ mount -t configfs none /config + +At this point, all default IIO groups will be created and can be accessed +under /config/iio. Next chapters will describe available IIO configuration +objects. + +3. Software triggers + +One of the IIO default configfs groups is the "triggers" groups. It is +automagically accessible when the configfs is mounted and can be found +under /config/iio/triggers. + +Software triggers are created under /config/iio/triggers directory. There +must exist an associated kernel module that implements a software trigger type. + +We support now the following software trigger types: + * hrtimer, uses high resolution timers as interrupt source implemened + by the iio-trig-hrtimer.c module. + +3.1 Software triggers creation and destruction + +As simply as: + +$ insmod iio-trig-hrtimer.ko +$ ls /config/triggers +hrtimer +$ mkdir /config/triggers/hrtimer/trig1 + +$ rmdir /config/triggers/hrtimer/trig1 +$ rmmod iio-trig-hrtimer + +Each trigger can have one or more attributes specific to the trigger type. + +3.2 "hrtimer" trigger types attributes + +"hrtimer" trigger type doesn't have any configurable attribute from /config dir, +but hrtimer triggers have the sampling_frequency attribute under /sys/bus/iio/devices/triggerX +directory. -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
