What:		/sys/bus/iio/devices/iio:deviceX/in_count0_preset
KernelVersion:	4.13
Contact:	fabrice.gasnier@st.com
Description:
		Reading returns the current preset value. Writing sets the
		preset value. Encoder counts continuously from 0 to preset
		value, depending on direction (up/down).

What:		/sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available
KernelVersion:	4.13
Contact:	fabrice.gasnier@st.com
Description:
		Reading returns the list possible quadrature modes.

What:		/sys/bus/iio/devices/iio:deviceX/in_count0_quadrature_mode
KernelVersion:	4.13
Contact:	fabrice.gasnier@st.com
Description:
		Configure the device counter quadrature modes:
		- non-quadrature:
			Encoder IN1 input servers as the count input (up
			direction).
		- quadrature:
			Encoder IN1 and IN2 inputs are mixed to get direction
			and count.

What:		/sys/bus/iio/devices/iio:deviceX/in_count_polarity_available
KernelVersion:	4.13
Contact:	fabrice.gasnier@st.com
Description:
		Reading returns the list possible active edges.

What:		/sys/bus/iio/devices/iio:deviceX/in_count0_polarity
KernelVersion:	4.13
Contact:	fabrice.gasnier@st.com
Description:
		Configure the device encoder/counter active edge:
		- rising-edge
		- falling-edge
		- both-edges

		In non-quadrature mode, device counts up on active edge.
		In quadrature mode, encoder counting scenarios are as follows:
		----------------------------------------------------------------
		| Active  | Level on |      IN1 signal    |     IN2 signal     |
		| edge    | opposite |------------------------------------------
		|         | signal   |  Rising  | Falling |  Rising  | Falling |
		----------------------------------------------------------------
		| Rising  | High ->  |   Down   |    -    |    Up    |    -    |
		| edge    | Low  ->  |    Up    |    -    |   Down   |    -    |
		----------------------------------------------------------------
		| Falling | High ->  |    -     |    Up   |    -     |   Down  |
		| edge    | Low  ->  |    -     |   Down  |    -     |    Up   |
		----------------------------------------------------------------
		| Both    | High ->  |   Down   |    Up   |    Up    |   Down  |
		| edges   | Low  ->  |    Up    |   Down  |   Down   |    Up   |
		----------------------------------------------------------------