linux-kernel - Re: [PATCH 1/2] dt-bindings: hwmon: Add binding for max6639

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Message-ID: <a55d973b-4504-a104-a889-f9b7e264c1e9@roeck-us.net>
Date:   Wed, 5 Oct 2022 11:40:25 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        Naresh Solanki <naresh.solanki@...ements.com>,
        devicetree@...r.kernel.org, Jean Delvare <jdelvare@...e.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Roland Stigge <stigge@...com.de>
Cc:     linux-kernel@...r.kernel.org, linux-hwmon@...r.kernel.org,
        Patrick Rudolph <patrick.rudolph@...ements.com>,
        Marcello Sylvester Bauer <sylv@...v.io>
Subject: Re: [PATCH 1/2] dt-bindings: hwmon: Add binding for max6639

On 9/21/22 23:34, Krzysztof Kozlowski wrote:
> On 22/09/2022 07:07, Naresh Solanki wrote:
>> From: Marcello Sylvester Bauer <sylv@...v.io>
>>
>> Add Devicetree binding documentation for Maxim MAX6639 temperature
>> monitor with PWM fan-speed controller.
>>
>> Signed-off-by: Marcello Sylvester Bauer <sylv@...v.io>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@...ements.com>
>> ---
>>   .../bindings/hwmon/maxim,max6639.yaml         | 112 ++++++++++++++++++
>>   1 file changed, 112 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>> new file mode 100644
>> index 000000000000..c845fb989af2
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>> @@ -0,0 +1,112 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +
>> +$id: http://devicetree.org/schemas/hwmon/maxim,max6639.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Maxim max6639
>> +
>> +maintainers:
>> +  - Roland Stigge <stigge@...com.de>
> 
> Ack from Roland is needed here.
> 
>> +
>> +description: |
>> +  The MAX6639 is a 2-channel temperature monitor with dual, automatic, PWM
>> +  fan-speed controller.  It monitors its own temperature and one external
>> +  diode-connected transistor or the temperatures of two external diode-connected
>> +  transistors, typically available in CPUs, FPGAs, or GPUs.
>> +
>> +  Datasheets:
>> +    https://datasheets.maximintegrated.com/en/ds/MAX6639-MAX6639F.pdf
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - maxim,max6639
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  '#address-cells':
>> +    const: 1
>> +
>> +  '#size-cells':
>> +    const: 0
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - "fan@0"
>> +  - "fan@1"
>> +
>> +additionalProperties: false
>> +
>> +patternProperties:
> 
> This goes after properties.
> 
>> +  "^fan@[0-1]$":
>> +    type: object
>> +    description: |
>> +      Represents the two fans and their specific configuration.
>> +
>> +    properties:
>> +      reg:
>> +        description: |
>> +          The fan number.
>> +        items:
> 
> Skip items.
> 
>> +          minimum: 0
>> +          maximum: 1
>> +
>> +      pwm-polarity:
> 
> Why is this property of fan, not of PWM source?
> 

The chip provides pwm output to the fan. That typical for fan
controller chips. Typically they also have options to configure
the pwm frequency and either pwm or DC output (max6639 does not
have the latter option).

Guenter