Re: [PATCH 3/5] dt-bindings: iio: adc: add ad7405 axi variant

[David Lechner <dlechner@baylibre.com>]

On 3/24/25 4:07 AM, Pop Ioan Daniel wrote:
> Add a new compatible and related bindings for the fpga-based ad7405 AXI

It's just a new compatible string. There don't seem to be any other related
bindings. So we don't need to say that in the description. 

And typically, FGPA is written in all caps.

> IP core, a variant of the generic AXI ADC IP.
> 
> The AXI AD7405 IP is a very similar HDL (fpga) variant of the generic
> AXI ADC IP, intended to control ad7405/adum770x family.

It helps the DT maintainers review if we can say specifically what the
difference is. In this case, I don't actually seen any registers that are
different from the generic AXI ADC IP block, so I'm not sure we actually need
a new compatible string in this case.

The REG_CHAN_USR_CNTRL_2 that you add in this series for the decimation rate
is documented in the generic IP block [1]. So the generic "adi,axi-adc-10.0.a"
should work. The chips that needed their own compatible have conflicting uses
for CUSTOM_CONTROL in the CNTRL_3 register, but it looks like this isn't used
for ad7405. 

[1]: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip

> 
> Signed-off-by: Pop Ioan Daniel <pop.ioan-daniel@analog.com>
> ---
>  Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
> index 4fa82dcf6fc9..1b02217ff8b5 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
> @@ -27,6 +27,7 @@ description: |
>        the ad7606 family.
>  
>    https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
> +  https://analogdevicesinc.github.io/hdl/library/axi_ad7405/index.html
>    http://analogdevicesinc.github.io/hdl/library/axi_ad7606x/index.html
>  
>  properties:
> @@ -34,6 +35,7 @@ properties:
>      enum:
>        - adi,axi-adc-10.0.a
>        - adi,axi-ad7606x
> +      - adi,axi-ad7405
>  
>    reg:
>      maxItems: 1