[PATCH v3 1/3] iio: types: add IIO_VOLUMEFLOW channel type

From: Wadim Mueller

Date: Sat May 30 2026 - 17:00:36 EST


Add a new IIO channel type for liquid volumetric flow sensors. The
unit exposed via the standard _scale attribute is litres per second
(l/s), so drivers reporting smaller native units (e.g. ml/min) only
need to set a fractional scale.

Update iio-core's name table, the iio_event_monitor whitelist and
the sysfs-bus-iio ABI document to match. The new _scale attribute is
folded into the existing shared _scale block; only the per-type _raw
needs a fresh entry.

Signed-off-by: Wadim Mueller <wafgo01@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-iio | 11 +++++++++++
drivers/iio/industrialio-core.c | 1 +
include/uapi/linux/iio/types.h | 1 +
tools/iio/iio_event_monitor.c | 2 ++
4 files changed, 15 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 5f87dcee7..2188557cb 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -507,6 +507,8 @@ What: /sys/bus/iio/devices/iio:deviceX/in_intensity_red_scale
What: /sys/bus/iio/devices/iio:deviceX/in_intensity_green_scale
What: /sys/bus/iio/devices/iio:deviceX/in_intensity_blue_scale
What: /sys/bus/iio/devices/iio:deviceX/in_concentration_co2_scale
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflow_scale
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflowY_scale
KernelVersion: 2.6.35
Contact: linux-iio@xxxxxxxxxxxxxxx
Description:
@@ -2458,3 +2460,12 @@ Description:
seconds, expressed as:

- a range specified as "[min step max]"
+
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflow_raw
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflowY_raw
+KernelVersion: 6.19
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Raw (unscaled) volumetric flow rate reading from the channel.
+ To convert to standard units (litres per second) apply the
+ channel's _scale (and _offset, when present).
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 22eefd048..aa34fcd8e 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -98,6 +98,7 @@ static const char * const iio_chan_type_name_spec[] = {
[IIO_CHROMATICITY] = "chromaticity",
[IIO_ATTENTION] = "attention",
[IIO_ALTCURRENT] = "altcurrent",
+ [IIO_VOLUMEFLOW] = "volumeflow",
};

static const char * const iio_modifier_names[] = {
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index 6d269b844..49480f321 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -53,6 +53,7 @@ enum iio_chan_type {
IIO_CHROMATICITY,
IIO_ATTENTION,
IIO_ALTCURRENT,
+ IIO_VOLUMEFLOW,
};

enum iio_modifier {
diff --git a/tools/iio/iio_event_monitor.c b/tools/iio/iio_event_monitor.c
index 03ca33869..078004750 100644
--- a/tools/iio/iio_event_monitor.c
+++ b/tools/iio/iio_event_monitor.c
@@ -65,6 +65,7 @@ static const char * const iio_chan_type_name_spec[] = {
[IIO_CHROMATICITY] = "chromaticity",
[IIO_ATTENTION] = "attention",
[IIO_ALTCURRENT] = "altcurrent",
+ [IIO_VOLUMEFLOW] = "volumeflow",
};

static const char * const iio_ev_type_text[] = {
@@ -193,6 +194,7 @@ static bool event_is_known(struct iio_event_data *event)
case IIO_CHROMATICITY:
case IIO_ATTENTION:
case IIO_ALTCURRENT:
+ case IIO_VOLUMEFLOW:
break;
default:
return false;
--
2.52.0