[PATCH v9 6/6] iio: ABI: Encourage differential voltage ABI usage

From: Marcelo Schmitt

Date: Mon Jul 27 2026 - 17:33:14 EST


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@xxxxxxxxxx>
---
No changes in v9.

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@xxxxxxxxxxxxxxx
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
--
2.53.0