Linux Device Drivers Development

The hrtimer trigger interface

The hrtimer trigger relies on the configfs filesystem (see Documentation/iio/iio_configfs.txt in kernel sources), which can be enabled through the CONFIG_IIO_CONFIGFS config option and mounted on our system (usually under the /config directory):

  # mkdir /config
  # mount -t configfs none /config

Now, loading the iio-trig-hrtimer module will create IIO groups accessible under /config/iio, allowing users to create hrtimer triggers under /config/iio/triggers/hrtimer, for example:

  # create a hrtimer trigger
  $ mkdir /config/iio/triggers/hrtimer/my_trigger_name
  # remove the trigger
  $ rmdir /config/iio/triggers/hrtimer/my_trigger_name  

Each hrtimer trigger contains a single sampling_frequency attribute in the trigger ...