Re: [PATCH v6 1/2] dt-bindings: iio: frequency: add admfm2000

["Nuno Sá" <noname.nuno@gmail.com>]

On Fri, 2024-01-19 at 08:31 +0000, Conor Dooley wrote:
> On Fri, Jan 19, 2024 at 09:20:01AM +0100, Nuno Sá wrote:
> > Hi Kim,
> > 
> > On Fri, 2024-01-19 at 00:30 +0000, Paller, Kim Seer wrote:
> > > > -----Original Message-----
> > > > From: Conor Dooley <conor@kernel.org>
> > > > Sent: Friday, January 19, 2024 12:10 AM
> > > > To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> > > > Cc: linux-iio@vger.kernel.org; devicetree@vger.kernel.org; linux-
> > > > kernel@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; Lars-Peter
> > > > Clausen <lars@metafoo.de>; Hennerich, Michael
> > > > <Michael.Hennerich@analog.com>; Rob Herring <robh+dt@kernel.org>;
> > > > Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley
> > > > <conor+dt@kernel.org>; Crt Mori <cmo@melexis.com>; Linus Walleij
> > > > <linus.walleij@linaro.org>; Bartosz Golaszewski <brgl@bgdev.pl>
> > > > Subject: Re: [PATCH v6 1/2] dt-bindings: iio: frequency: add admfm2000
> > > > 
> > > > [External]
> > > > 
> > > > Hey,
> > > > 
> > > > On Thu, Jan 18, 2024 at 04:58:55PM +0800, Kim Seer Paller wrote:
> > > > > Dual microwave down converter module with input RF and LO frequency
> > > > > ranges from 0.5 to 32 GHz and an output IF frequency range from 0.1 to
> > > > > 8 GHz. It consists of a LNA, mixer, IF filter, DSA, and IF amplifier
> > > > > for each down conversion path.
> > > > > 
> > > > > Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> > > > > ---
> > > > > V5 -> V6: Moved array of switch and attenuation GPIOs to the channel node.
> > > > >           Changed pin coords with friendly names. Removed Reviewed-by tag.
> > > > > V4 -> V5: Added Reviewed-by tag.
> > > > > V3 -> V4: Updated the description of the properties with multiple entries
> > > > > and
> > > > >           defined the order.
> > > > > V2 -> V3: Adjusted indentation to resolve wrong indentation warning.
> > > > >           Changed node name to converter. Updated the descriptions to
> > > > > clarify
> > > > >           the properties.
> > > > > V1 -> V2: Removed '|' after description. Specified the pins connected to
> > > > >           the GPIOs. Added additionalProperties: false. Changed node name
> > > > > to
> > > > gpio.
> > > > >           Aligned < syntax with the previous syntax in the examples.
> > > > > 
> > > > >  .../bindings/iio/frequency/adi,admfm2000.yaml | 129 ++++++++++++++++++
> > > > >  MAINTAINERS                                   |   7 +
> > > > >  2 files changed, 136 insertions(+)
> > > > >  create mode 100644
> > > > Documentation/devicetree/bindings/iio/frequency/adi,admfm2000.yaml
> > > > > 
> > > > > diff --git
> > > > a/Documentation/devicetree/bindings/iio/frequency/adi,admfm2000.yaml
> > > > b/Documentation/devicetree/bindings/iio/frequency/adi,admfm2000.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..6f2c91c38666
> > > > > --- /dev/null
> > > > > +++
> > > > b/Documentation/devicetree/bindings/iio/frequency/adi,admfm2000.yaml
> > > > > @@ -0,0 +1,129 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > > +# Copyright 2023 Analog Devices Inc.
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/iio/frequency/adi,admfm2000.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: ADMFM2000 Dual Microwave Down Converter
> > > > > +
> > > > > +maintainers:
> > > > > +  - Kim Seer Paller <kimseer.paller@analog.com>
> > > > > +
> > > > > +description:
> > > > > +  Dual microwave down converter module with input RF and LO frequency
> > > > ranges
> > > > > +  from 0.5 to 32 GHz and an output IF frequency range from 0.1 to 8 GHz.
> > > > > +  It consists of a LNA, mixer, IF filter, DSA, and IF amplifier for each
> > > > > down
> > > > > +  conversion path.
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    enum:
> > > > > +      - adi,admfm2000
> > > > > +
> > > > > +  '#address-cells':
> > > > > +    const: 1
> > > > > +
> > > > > +  '#size-cells':
> > > > > +    const: 0
> > > > > +
> > > > > +patternProperties:
> > > > > +  "^channel@[0-1]$":
> > > > > +    type: object
> > > > > +    description: Represents a channel of the device.
> > > > > +
> > > > > +    additionalProperties: false
> > > > > +
> > > > > +    properties:
> > > > > +      reg:
> > > > > +        description:
> > > > > +          The channel number.
> > > > > +        minimum: 0
> > > > > +        maximum: 1
> > > > > +
> > > > > +      adi,mode:
> > > > > +        description:
> > > > > +          RF path selected for the channel.
> > > > > +            0 - Direct IF mode
> > > > > +            1 - Mixer mode
> > > > > +        $ref: /schemas/types.yaml#/definitions/uint32
> > > > > +        enum: [0, 1]
> > > > 
> > > > How come this is an enum, rather than a boolean property such as
> > > > "adi,mixer-mode"?
> > > 
> > > I used an enum, perhaps because it was easier to implement. However, this
> > > could be changed if a boolean property might be more suitable in this case.
> > > Is that the preferred option?
> > > 
> > 
> > Hmmm, How is the enum easier than a boolean property :)? I guess the device has a
> > default mode. So, if it is Direct IF mode you have 'adi,mixer-mode' to enable
> > that
> > mode and that's it. So the code is pretty much just:
> > 
> > if (device_property_read_bool()) {
> 
> device_property_present() is preferred I think.
> 

Hmm, don't want to start an argument but I'm not sure either :). I would argue that
device_property_read_bool() has more users (according to git grep - and if I did not
mess the grep) and it pretty much wraps device_property_present(). So, if there was
no value in it's "meaning" we would/should stop using it and eventually drop it...
Anyways, not really a big deal.

- Nuno Sá
> >