A new compatible is added to reflect the specialized version of the HDL.
We use the parallel interface to write the ADC's registers, and
accessing this interface requires to use
ADI_AXI_REG_CONFIG_RD,ADI_AXI_REG_CONFIG_WR and ADI_AXI_REG_CONFIG_CTRL
in a custom fashion.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
---
 .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   | 53 ++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
index e1f450b80db2..6c3fc44422cc 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
@@ -17,13 +17,22 @@ description: |
   interface for the actual ADC, while this IP core will interface
   to the data-lines of the ADC and handle the streaming of data into
   memory via DMA.
+  In some cases, the AXI ADC interface is used to perform specialized
+  operation to a particular ADC, e.g access the physical bus through
+  specific registers to write ADC registers.
+  In this case, we use a different compatible whch indicates the target
+  chip(s)'s name.
+  The following IP is currently supported:
+    -axi_ad7606X: Backend for all the chips from the ad7606 family.
 
   https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
+  http://analogdevicesinc.github.io/hdl/library/axi_ad7606x/index.html
 
 properties:
   compatible:
     enum:
       - adi,axi-adc-10.0.a
+      - adi,axi-ad7606x
 
   reg:
     maxItems: 1
@@ -53,6 +62,24 @@ required:
   - reg
   - clocks
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: adi,axi-ad7606x
+    then:
+      patternProperties:
+        "^adc@[0-9a-f]+$":
+          type: object
+          properties:
+            reg:
+              maxItems: 1
+          additionalProperties: true
+          required:
+            - compatible
+            - reg
+
 additionalProperties: false
 
 examples:
@@ -65,4 +92,30 @@ examples:
         clocks = <&axi_clk>;
         #io-backend-cells = <0>;
     };
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    axi-adc@44a00000 {
+        compatible = "adi,axi-ad7606x";
+        reg = <0x44a00000 0x10000>;
+        dmas = <&rx_dma 0>;
+        dma-names = "rx";
+        clocks = <&ext_clk>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adi_adc@0 {
+            compatible = "adi,ad7606b";
+            reg = <0>;
+            pwms = <&axi_pwm_gen 0 0>;
+            pwm-names = "cnvst_n";
+            avcc-supply = <&adc_vref>;
+            reset-gpios = <&gpio0 91 GPIO_ACTIVE_HIGH>;
+            standby-gpios = <&gpio0 90 GPIO_ACTIVE_LOW>;
+            adi,range-gpios = <&gpio0 89 GPIO_ACTIVE_HIGH>;
+            adi,oversampling-ratio-gpios = <&gpio0 88 GPIO_ACTIVE_HIGH
+                            &gpio0 87 GPIO_ACTIVE_HIGH
+                            &gpio0 86 GPIO_ACTIVE_HIGH>;
+            io-backends = <&iio_backend>;
+        };
+    };
 ...

-- 
2.34.1

On 12/10/24 4:46 AM, Guillaume Stols wrote:
> A new compatible is added to reflect the specialized version of the HDL.
> We use the parallel interface to write the ADC's registers, and
> accessing this interface requires to use
> ADI_AXI_REG_CONFIG_RD,ADI_AXI_REG_CONFIG_WR and ADI_AXI_REG_CONFIG_CTRL
> in a custom fashion.
> 
> Signed-off-by: Guillaume Stols <gstols@baylibre.com>
> ---
>  .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   | 53 ++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
> index e1f450b80db2..6c3fc44422cc 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
> @@ -17,13 +17,22 @@ description: |
>    interface for the actual ADC, while this IP core will interface
>    to the data-lines of the ADC and handle the streaming of data into
>    memory via DMA.
> +  In some cases, the AXI ADC interface is used to perform specialized
> +  operation to a particular ADC, e.g access the physical bus through
> +  specific registers to write ADC registers.
> +  In this case, we use a different compatible whch indicates the target

s/whch/which/

> +  chip(s)'s name.

s/chip(s)'s/IP core's/

> +  The following IP is currently supported:
> +    -axi_ad7606X: Backend for all the chips from the ad7606 family.

s/axi_ad7606X/AXI AD7606X/ # proper name of the IP core
s/Backend/Specialized version of the IP core/

>  
>    https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
> +  http://analogdevicesinc.github.io/hdl/library/axi_ad7606x/index.html
>  
>  properties:
>    compatible:
>      enum:
>        - adi,axi-adc-10.0.a
> +      - adi,axi-ad7606x
>  
>    reg:
>      maxItems: 1
> @@ -53,6 +62,24 @@ required:
>    - reg
>    - clocks
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: adi,axi-ad7606x
> +    then:
> +      patternProperties:
> +        "^adc@[0-9a-f]+$":
> +          type: object
> +          properties:
> +            reg:
> +              maxItems: 1
> +          additionalProperties: true
> +          required:
> +            - compatible
> +            - reg
> +

The preferred way to compatible-specific bindings is to add
everything at the top level and then disable ones that don't
apply using -if: blocks.

So under the top-level properties:, add

  '#address-cells':
    const: 1
  '#size-cells':
    const 0

and move the patternProperties: to the top level.

Then add not: to the -if: and make the then:

    properties:
      '#address-cells': false
      '#size-cells': false
    patternProperties:
      "^adc@[0-9a-f]+$": false

>  additionalProperties: false
>  
>  examples:
> @@ -65,4 +92,30 @@ examples:
>          clocks = <&axi_clk>;
>          #io-backend-cells = <0>;
>      };
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    axi-adc@44a00000 {

Shouldn't we have the label iio_backend: here?

Also, could use a more generic name like "parallel-bus-controller"
instead of "axi-adc".

> +        compatible = "adi,axi-ad7606x";
> +        reg = <0x44a00000 0x10000>;
> +        dmas = <&rx_dma 0>;
> +        dma-names = "rx";
> +        clocks = <&ext_clk>;
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adi_adc@0 {
> +            compatible = "adi,ad7606b";
> +            reg = <0>;
> +            pwms = <&axi_pwm_gen 0 0>;
> +            pwm-names = "cnvst_n";
> +            avcc-supply = <&adc_vref>;
> +            reset-gpios = <&gpio0 91 GPIO_ACTIVE_HIGH>;
> +            standby-gpios = <&gpio0 90 GPIO_ACTIVE_LOW>;
> +            adi,range-gpios = <&gpio0 89 GPIO_ACTIVE_HIGH>;
> +            adi,oversampling-ratio-gpios = <&gpio0 88 GPIO_ACTIVE_HIGH
> +                            &gpio0 87 GPIO_ACTIVE_HIGH
> +                            &gpio0 86 GPIO_ACTIVE_HIGH>;
> +            io-backends = <&iio_backend>;
> +        };
> +    };
>  ...
>

On Tue, 10 Dec 2024 10:46:42 +0000, Guillaume Stols wrote:
> A new compatible is added to reflect the specialized version of the HDL.
> We use the parallel interface to write the ADC's registers, and
> accessing this interface requires to use
> ADI_AXI_REG_CONFIG_RD,ADI_AXI_REG_CONFIG_WR and ADI_AXI_REG_CONFIG_CTRL
> in a custom fashion.
> 
> Signed-off-by: Guillaume Stols <gstols@baylibre.com>
> ---
>  .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   | 53 ++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.example.dtb: axi-adc@44a00000: '#address-cells', '#size-cells', 'adi_adc@0' do not match any of the regexes: 'pinctrl-[0-9]+'
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,axi-adc.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.example.dtb: adi_adc@0: pwm-names:0: 'convst1' was expected
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7606.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.example.dtb: adi_adc@0: pwm-names: ['cnvst_n'] is too short
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7606.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.example.dtb: adi_adc@0: 'vdrive-supply' is a required property
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7606.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20241210-ad7606_add_iio_backend_software_mode-v2-2-6619c3e50d81@baylibre.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.