[PATCH v2 4/8] dt-bindings: iio: adc: add input-channel-rotation property

[David Lechner (TI)]

Add a generic input-channel-rotation property to adc.yaml. This is a
feature seen frequently in ADCs that are designed to measure resistive
loads, such as RTDs and strain gauges. Enabling this can reduce offset
errors by swapping the positive and negative input channels on every
other conversion. This can have side-effects in timing and filter
response, so it is not always desirable to enable this feature in some
applications. Therefore, it is best to make this a property that can be
enabled or disabled in the device tree.

Signed-off-by: David Lechner (TI) <dlechner@xxxxxxxxxxxx>
---
v2 changes:
* New patch.
---
 Documentation/devicetree/bindings/iio/adc/adc.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adc.yaml b/Documentation/devicetree/bindings/iio/adc/adc.yaml
index 9ec1f447b565..3d52c00922c9 100644
--- a/Documentation/devicetree/bindings/iio/adc/adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adc.yaml
@@ -81,6 +81,13 @@ properties:
       ADCs usually allow choosing between internal reference sources or a pair
       of external pins.
 
+  input-channel-rotation:
+    type: boolean
+    description:
+      If set, the positive and negative input channels are allowed to be swapped
+      on every other conversion to reduce offset errors. This is also referred
+      to as "chop" in some datasheets.
+
   excitation-channels:
     $ref: /schemas/types.yaml#/definitions/uint32-array
     description:

-- 
2.43.0