Re: [PATCH v8 5/5] iio: ABI: Encourage differential voltage ABI usage

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 23 Jul 2026 16:53:35 -0300
Marcelo Schmitt <marcelo.schmitt@analog.com> wrote:

> So far, parts that could only do differential voltage measurements were
> only required to have a consistent labeling of their channels by complying
> either to voltageY or to voltageY-voltageZ ABI. Over time, code maintainers
> came to the conclusion that the voltageY-voltageZ ABI is better suited for
> differential-only chips as it provides a simple indication to users that
> the channels measure the difference of two inputs.
> 
> Adjust the ABI documentation to recommend using the voltageY-voltageZ ABI
> for chips that do only differential voltage measurements.
> 
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> ---
> New patch in v8.
> 
> The updated ABI doc might not have gotten very clear, so I'm completely fine
> with any modifications to this patch. Also, since the documentation update is
> minimal, doesn't add any new ABI, and might be picked up through Jonathan's
> tree, I'm not CCing the documentaion mailing list.
> 
Looks fine to me.  

I looked through the rest of the series and other than the thing you've
suggested doing of dropping the slightly more complex part for now, looks
good to me.  Feel free to send a v9 whenever you have it ready.  This is
near enough merge I don't mind going a bit quicker than normal.

Jonathan

>  Documentation/ABI/testing/sysfs-bus-iio | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index 5cc2e82c4997..7446e07b9ab2 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -162,10 +162,11 @@ Contact:	linux-iio@vger.kernel.org
>  Description:
>  		Raw (unscaled) differential voltage measurement equivalent to
>  		channel Y - channel Z where these channel numbers apply to the
> -		physically equivalent inputs when non differential readings are
> -		separately available. In differential only parts, then all that
> -		is required is a consistent labeling.  Units after application
> -		of scale and offset are millivolts.
> +		physically equivalent inputs when non-differential readings are
> +		separately available. Even though differential-only parts had
> +		been merely required to have consistent channel labeling, this
> +		ABI is preferred over the non-differential one for those chips.
> +		Units after application of scale and offset are millivolts.
>  
>  What:		/sys/bus/iio/devices/iio:deviceX/in_altvoltageY_rms_raw
>  KernelVersion:	6.18