On Sun, Nov 02, 2025 at 10:57:11AM +0000, Jonathan Cameron wrote:
> 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?

And if it is to be kept, I would like the modes to become strings, not
"random" integers. Although, as you say, feels like something software
could just control