From: Angelo Dureghello <adureghello@baylibre.com>

Add gain calibration support by a per-channel resistor value.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 .../devicetree/bindings/iio/adc/adi,ad7606.yaml    | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
index 29f12d650442b8ff2eb455306ce59a0e87867ddd..d4b8ea51f60be367e79a4db18d932cbca9c7dc91 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
@@ -204,6 +204,15 @@ patternProperties:
           considered a bipolar differential channel. Otherwise it is bipolar
           single-ended.
 
+      adi,rfilter-ohms:
+        description:
+          For ADCs that supports gain calibration, this property must be set to
+          the value of the external RFilter resistor. Proper gain error
+          correction is applied based on this value.
+        default: 0
+        minimum: 0
+        maximum: 65536
+
     required:
       - reg
       - bipolar
@@ -256,6 +265,25 @@ allOf:
       properties:
         adi,oversampling-ratio-gpios: false
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad7605-4
+              - adi,ad7606-4
+              - adi,ad7606-6
+              - adi,ad7606-8
+              - adi,ad7607
+              - adi,ad7608
+              - adi,ad7609
+              - adi,ad7616
+    then:
+      patternProperties:
+        "^channel@[0-9a-f]+$":
+          properties:
+            adi,rfilter-ohms: false
+
   - if:
       properties:
         compatible:
@@ -398,6 +426,7 @@ examples:
                 reg = <8>;
                 diff-channels = <8 8>;
                 bipolar;
+                adi,rfilter-ohms = <2048>;
             };
 
         };

-- 
2.49.0

On 5/2/25 8:27 AM, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add gain calibration support by a per-channel resistor value.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---
>  .../devicetree/bindings/iio/adc/adi,ad7606.yaml    | 29 ++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> index 29f12d650442b8ff2eb455306ce59a0e87867ddd..d4b8ea51f60be367e79a4db18d932cbca9c7dc91 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> @@ -204,6 +204,15 @@ patternProperties:
>            considered a bipolar differential channel. Otherwise it is bipolar
>            single-ended.
>  
> +      adi,rfilter-ohms:
> +        description:
> +          For ADCs that supports gain calibration, this property must be set to
> +          the value of the external RFilter resistor. Proper gain error
> +          correction is applied based on this value.
> +        default: 0
> +        minimum: 0
> +        maximum: 65536
> +
Max should be 64512.

On Fri, May 02, 2025 at 03:27:01PM +0200, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add gain calibration support by a per-channel resistor value.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---
>  .../devicetree/bindings/iio/adc/adi,ad7606.yaml    | 29 ++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> index 29f12d650442b8ff2eb455306ce59a0e87867ddd..d4b8ea51f60be367e79a4db18d932cbca9c7dc91 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> @@ -204,6 +204,15 @@ patternProperties:
>            considered a bipolar differential channel. Otherwise it is bipolar
>            single-ended.
>  
> +      adi,rfilter-ohms:
> +        description:
> +          For ADCs that supports gain calibration, this property must be set to
> +          the value of the external RFilter resistor. Proper gain error
> +          correction is applied based on this value.
> +        default: 0
> +        minimum: 0

Perhaps obvious to those working on these ADCs, but this is a series
resistor so a default of zero for the existing devices makes sense.
Acked-by: Conor Dooley <conor.dooley@microchip.com>

> +        maximum: 65536
> +
>      required:
>        - reg
>        - bipolar
> @@ -256,6 +265,25 @@ allOf:
>        properties:
>          adi,oversampling-ratio-gpios: false
>  
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - adi,ad7605-4
> +              - adi,ad7606-4
> +              - adi,ad7606-6
> +              - adi,ad7606-8
> +              - adi,ad7607
> +              - adi,ad7608
> +              - adi,ad7609
> +              - adi,ad7616
> +    then:
> +      patternProperties:
> +        "^channel@[0-9a-f]+$":
> +          properties:
> +            adi,rfilter-ohms: false
> +
>    - if:
>        properties:
>          compatible:
> @@ -398,6 +426,7 @@ examples:
>                  reg = <8>;
>                  diff-channels = <8 8>;
>                  bipolar;
> +                adi,rfilter-ohms = <2048>;
>              };
>  
>          };
> 
> -- 
> 2.49.0
>