Linux Device Drivers Development

Tying a device with a trigger

Associating a device with a given trigger consists of writing the name of the trigger to the current_trigger file available under the device's trigger directory. For example, let's say we need to tie a device with the trigger that has index 2:

# set trigger2 as current trigger for device0
# echo sysfstrig2 >    /sys/bus/iio/devices/iio:device0/trigger/current_trigger  

To detach the trigger from the device, you should write an empty string to the current_trigger file of the device trigger directory, shown as follows:

# echo "" > iio:device0/trigger/current_trigger  

We will see further on in the chapter a practical example dealing with the sysfs trigger for data capture.