Re: [PATCH v6 03/16] iio: ABI: add parent entry for iio channels

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 18 Jun 2026 14:27:19 +0100
Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@kernel.org> wrote:

> From: Rodrigo Alencar <rodrigo.alencar@analog.com>
> 
> Add documentation for a read-only sysfs attribute that allows to expose
> parent-child relationships between IIO channels.
> 
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
> ---
>  Documentation/ABI/testing/sysfs-bus-iio | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index d9c4e3b53f29..e0f11b39511f 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -2154,6 +2154,23 @@ Description:
>  		specific attributes. This is useful for userspace to be able to
>  		better identify an individual channel.
>  
> +What:		/sys/bus/iio/devices/iio:deviceX/in_voltageY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/in_altvoltageY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/in_currentY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/out_currentY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/in_altcurrentY_parent
> +What:		/sys/bus/iio/devices/iio:deviceX/out_altcurrentY_parent
> +KernelVersion:	7.2
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Read-only attribute containing the sysfs name prefix of the parent
> +		channel for hierarchical channel relationships (e.g. "out_altvoltage0").
> +		The prefix uniquely identifies the parent channel and can be used by
> +		userspace to organize channels in tree-like structures that reflects
> +		the physical or logical relationships between them.

Reading this again after a while (sorry for delay) I think this needs a motivating
example to remind us what this means.

> +
>  What:		/sys/bus/iio/devices/iio:deviceX/in_phaseY_raw
>  KernelVersion:	4.18
>  Contact:	linux-iio@vger.kernel.org
>