Re: [PATCH 1/3] dt-bindings: iio: amplifiers: add adl8113

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 31 Oct 2025 16:04:03 +0000
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add devicetree bindings for adl8113.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
>  .../bindings/iio/amplifiers/adi,adl8113.yaml  | 76 +++++++++++++++++++
>  1 file changed, 76 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,adl8113.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/amplifiers/adi,adl8113.yaml b/Documentation/devicetree/bindings/iio/amplifiers/adi,adl8113.yaml
> new file mode 100644
> index 000000000000..4cc21c93233c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,adl8113.yaml
> @@ -0,0 +1,76 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/amplifiers/adi,adl8113.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices ADL8113 Low Noise Amplifier with integrated bypass switches
> +
> +maintainers:
> +  - Antoniu Miclaus <antoniu.miclaus@analog.com>
> +
> +description: |
> +  The ADL8113 is a 10MHz to 12GHz Low Noise Amplifier with integrated bypass
> +  switches controlled by two GPIO pins (VA and VB). The device supports four
> +  operation modes:
> +    - Internal Amplifier: VA=0, VB=0 - Signal passes through the internal LNA
> +    - Internal Bypass: VA=1, VB=1 - Signal bypasses through internal path
> +    - External Bypass A: VA=0, VB=1 - Signal routes through external bypass path A
> +    - External Bypass B: VA=1, VB=0 - Signal routes through external bypass path B

These two external paths are a problem for description because there could be
literally anything between those OUT_A and IN_A etc.  To be useful it might be necessary
to describe that circuitry. 

> +
> +    https://www.analog.com/en/products/adl8113.html
> +
> +properties:
> +  compatible:
> +    const: adi,adl8113
> +
> +  vdd1-supply: true
> +
> +  vdd2-supply: true
> +
> +  vss2-supply: true
> +
> +  va-gpios:
> +    description:
> +      GPIO connected to the VA control pin. Must be specified as GPIO_ACTIVE_HIGH.
> +    maxItems: 1
> +
> +  vb-gpios:
> +    description:
> +      GPIO connected to the VB control pin. Must be specified as GPIO_ACTIVE_HIGH.
> +    maxItems: 1
> +
> +  adi,initial-mode:
> +    description: |
> +      Initial operation mode after device initialization
> +        0 - Internal Amplifier (default)
> +        1 - Internal Bypass
> +        2 - External Bypass A
> +        3 - External Bypass B
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [0, 1, 2, 3]
> +    default: 0

Given this only takes affect when the driver loads anyway, why have
an initial mode in DT?

> +
> +required:
> +  - compatible
> +  - va-gpios
> +  - vb-gpios
> +  - vdd1-supply
> +  - vdd2-supply
> +  - vss2-supply
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    amplifier {
> +        compatible = "adi,adl8113";
> +        va-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
> +        vb-gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
> +        vdd1-supply = <&vdd1_5v>;
> +        vdd2-supply = <&vdd2_3v3>;
> +        vss2-supply = <&vss2_neg>;
> +        adi,initial-mode = <0>;
> +    };
> +...