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

[Guenter Roeck <linux@roeck-us.net>]

On 1/28/20 8:30 PM, Logan Shaw wrote:
> 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]"
> 

That seems highly unusual and would be quite messy to implement.
I don't see the point of having the chip name in individual properties.

Guenter

>>
>>> +    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
>>>