[PATCH v2 2/8] dt-bindings: iio: adc: Add excitation current sources properties

[David Lechner]

From: Kurt Borja <kuurtb@xxxxxxxxx>

Some ADCs incorporate current sources that provide excitation current to
resistive temperature devices (RTDs), thermistors, diodes and other
resistive sensors that require constant current biasing.

Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
Signed-off-by: David Lechner (TI) <dlechner@xxxxxxxxxxxx>
---
v2 changes (compared to Kurt's RFC v2):
* Make units nanoamps instead of microamps to fit known devices.
* Drop bit about allowing single value for multiple channels.
* Add bit about semantics of the array index.
---
 Documentation/devicetree/bindings/iio/adc/adc.yaml | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adc.yaml b/Documentation/devicetree/bindings/iio/adc/adc.yaml
index 12800737d4fb..860601ec5334 100644
--- a/Documentation/devicetree/bindings/iio/adc/adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adc.yaml
@@ -81,6 +81,26 @@ properties:
       ADCs usually allow choosing between internal reference sources or a pair
       of external pins.
 
+  excitation-channels:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description:
+      Excitation current sources provide current to resistive temperature
+      devices (RTDs), thermistors, diodes and other resistive sensors that
+      require constant current biasing.
+
+      This array describes the mux configuration of the excitation current
+      sources.
+
+  excitation-current-nanoamp:
+    description:
+      Excitation current sources provide current to resistive temperature
+      devices (RTDs), thermistors, diodes and other resistive sensors that
+      require constant current biasing.
+
+      This array describes the current configuration of the excitation current
+      sources. The index in the array corresponds to the same index in the
+      excitation-channels array.
+
 anyOf:
   - oneOf:
       - required:

-- 
2.43.0