Re: [PATCH v6 2/2] dt-bindings: hwmon: (adt7475) Added missing adt7475 documentation

[Logan Shaw <Logan.Shaw@alliedtelesis.co.nz>]

On Mon, 2020-01-27 at 09:48 -0600, Rob Herring wrote:
> On Mon, Jan 27, 2020 at 11:10:14AM +1300, Logan Shaw wrote:
> > Added a new file documenting the adt7475 devicetree and added the
> > four
> > new properties to it.
> > 
> > Signed-off-by: Logan Shaw <logan.shaw@alliedtelesis.co.nz>
> > ---
> > ---
> >  .../devicetree/bindings/hwmon/adt7475.yaml    | 95
> > +++++++++++++++++++
> >  1 file changed, 95 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/hwmon/adt7475.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/hwmon/adt7475.yaml
> > b/Documentation/devicetree/bindings/hwmon/adt7475.yaml
> > new file mode 100644
> > index 000000000000..450da5e66e07
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/adt7475.yaml
> > @@ -0,0 +1,95 @@
> > +# SPDX-License-Identifier: GPL-2.0
> 
> Dual license new bindings please:
> 
> (GPL-2.0-only OR BSD-2-Clause)
> 
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/adt7475.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ADT7475 hwmon sensor
> > +
> > +maintainers:
> > +  - Jean Delvare <jdelvare@suse.com>
> > +
> > +description: |
> > +  The ADT7473, ADT7475, ADT7476, and ADT7490 are thermal monitors
> > and multiple
> > +  PWN fan controllers.
> > +
> > +  They support monitoring and controlling up to four fans (the
> > ADT7490 can only
> > +  control up to three). They support reading a single on chip
> > temperature
> > +  sensor and two off chip temperature sensors (the ADT7490
> > additionally
> > +  supports measuring up to three current external temperature
> > sensors with
> > +  series resistance cancellation (SRC)).
> > +
> > +  Datasheets:
> > +  https://www.onsemi.com/pub/Collateral/ADT7473-D.PDF
> > +  https://www.onsemi.com/pub/Collateral/ADT7475-D.PDF
> > +  https://www.onsemi.com/pub/Collateral/ADT7476-D.PDF
> > +  https://www.onsemi.com/pub/Collateral/ADT7490-D.PDF
> > +
> > +  Description taken from omsemiconductors specification sheets,
> > with minor
> 
> omsemi?
>  ^
> 
> > +  rephrasing.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - adi,adt7473
> > +      - adi,adt7475
> > +      - adi,adt7476
> > +      - adi,adt7490
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  bypass-attenuator-in0:
> 
> Needs a vendor prefix and a type ref. 

Adi (Analog Devices) sold the ADT product line (amongst other things)
to On Semiconductor. As changing the vendor of these chips (in code)
would break backwards compatibility should we keep the vendor as adi?

To confirm, would this make the property "adi,adt7476,bypass-
attenuator-in0"?

So used in conjunction with patternProperties you would end up with
something like:

"adi,(adt7473|adt7475|adt7476|adt7490),bypass-attenuator-in[0134]"

> 
> > +    description: |
> > +      Configures bypassing the individual voltage input
> > +      attenuator, on in0. This is supported on the ADT7476 and
> > ADT7490.
> > +      If set to a non-zero integer the attenuator is bypassed, if
> > set to
> > +      zero the attenuator is not bypassed. If the property is
> > absent then
> > +      the config register is not modified.
> 
> Sounds like this could be boolean? If not, define a schema for what
> are 
> valid values.
> 
> > +    maxItems: 1
> > +
> > +  bypass-attenuator-in1:
> > +    description: |
> > +      Configures bypassing the individual voltage input
> > +      attenuator, on in1. This is supported on the ADT7473,
> > ADT7475,
> > +      ADT7476 and ADT7490. If set to a non-zero integer the
> > attenuator
> > +      is bypassed, if set to zero the attenuator is not bypassed.
> > If the
> > +      property is absent then the config register is not modified.
> > +    maxItems: 1
> > +
> > +  bypass-attenuator-in3:
> > +    description: |
> > +      Configures bypassing the individual voltage input
> > +      attenuator, on in3. This is supported on the ADT7476 and
> > ADT7490.
> > +      If set to a non-zero integer the attenuator is bypassed, if
> > set to
> > +      zero the attenuator is not bypassed. If the property is
> > absent then
> > +      the config register is not modified.
> > +    maxItems: 1
> > +
> > +  bypass-attenuator-in4:
> 
> These 4 could be a single entry under patternProperties.
> 
> 
> > +    description: |
> > +      Configures bypassing the individual voltage input
> > +      attenuator, on in4. This is supported on the ADT7476 and
> > ADT7490.
> > +      If set to a non-zero integer the attenuator is bypassed, if
> > set to
> > +      zero the attenuator is not bypassed. If the property is
> > absent then
> > +      the config register is not modified.
> > +    maxItems: 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +
> > +examples:
> > +  - |
> > +    i2c {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      hwmon@2e {
> > +        compatible = "adi,adt7476";
> > +        reg = <0x2e>;
> > +        bypass-attenuator-in0 = <1>;
> > +        bypass-attenuator-in1 = <0>;
> > +      };
> > +    };
> > +...
> > -- 
> > 2.25.0
> >