[PATCH 2/6] dt-bindings: iio: adc: ad7380: fix ad7380-4 reference supply

[Julien Stephan]

ad7380-4 is the only device from ad738x family that doesn't have an
internal reference. Moreover its external reference is called REFIN in
the datasheet while all other use REFIO as an optional external
reference. If refio-supply is omitted the internal reference is
used.

Fix the binding by adding refin-supply and makes it required for
ad7380-4 only.

Fixes: 1a291cc8ee17 ("dt-bindings: iio: adc: ad7380: add support for ad738x-4 4 channels variants")
Signed-off-by: Julien Stephan <jstephan@xxxxxxxxxxxx>
---
 .../devicetree/bindings/iio/adc/adi,ad7380.yaml        | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
index 72c51b3de97b..74d82721637c 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
@@ -58,6 +58,7 @@ properties:
   vcc-supply: true
   vlogic-supply: true
   refio-supply: true
+  refin-supply: true
 
   aina-supply:
     description:
@@ -127,6 +128,23 @@ allOf:
         ainc-supply: false
         aind-supply: false
 
+  # ad7380-4 uses refin-supply as external reference.
+  # All other chips from ad738x family use refio as optional external reference.
+  # When refio-supply is omitted, internal reference is used.
+  - if:
+      properties:
+        compatible:
+          enum:
+            - adi,ad7380-4
+    then:
+      properties:
+        refio-supply: false
+      required:
+        - refin-supply
+    else:
+      properties:
+        refin-supply: false
+
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>

-- 
2.46.0