[PATCH v2 3/3] dt-bindings: hwmon: max31790: Add maxim,pwmout-pin-as-tach-input property

Chanh Nguyen chanh at amperemail.onmicrosoft.com
Tue Apr 16 14:52:58 AEST 2024



On 14/04/2024 13:07, Krzysztof Kozlowski wrote:
> On 14/04/2024 06:22, Chanh Nguyen wrote:
>> The max31790 supports six pins, which are dedicated PWM outputs. Any of the
>> six PWM outputs can also be configured to serve as tachometer inputs,
>> allowing for up to 12 tachometer fans to be monitored.
>>
>> Add a new vendor-specific property, 'maxim,pwmout-pin-as-tach-input',
>> to allow PWMOUT to become a TACH input.
>>
>> An array of six integers responds to six PWM channels for configuring
>> the PWM to TACH mode. When set to 0, the associated PWMOUT produces
>> a PWM waveform for control of fan speed. When set to 1, PWMOUT becomes
>> a TACH input.
>>
>> Signed-off-by: Chanh Nguyen <chanh at os.amperecomputing.com>
>> ---
>> Changes in v2:
>>   - Update the vendor property name to "maxim,pwmout-pin-as-tach-input"   [Rob]
>>   - Update commit message                                                 [Krzysztof]
> 
> Please put binding before its user.
> 

Hi Krzysztof, I'll drop this [Path 3/3] in the patch series v3.

My patch series will only be two patches. They are "dt-bindings: hwmon: 
Add maxim max31790" and "hwmon: (max31790): Support config PWM output 
becomes TACH"

>> ---
>>   .../devicetree/bindings/hwmon/maxim,max31790.yaml     | 11 +++++++++++
>>   1 file changed, 11 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml
>> index a561e5a3e9e4..2d4f50bc7c41 100644
>> --- a/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml
>> +++ b/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml
>> @@ -30,6 +30,16 @@ properties:
>>     resets:
>>       maxItems: 1
>>   
>> +  maxim,pwmout-pin-as-tach-input:
>> +    description: |
>> +      An array of six integers responds to six PWM channels for
>> +      configuring the pwm to tach mode.
>> +      When set to 0, the associated PWMOUT produces a PWM waveform for
>> +      control of fan speed. When set to 1, PWMOUT becomes a TACH input
>> +    $ref: /schemas/types.yaml#/definitions/uint8-array
>> +    maxItems: 6
>> +    minItems: 6
> 
> tach-ch solves your case. You define which inputs should be used for tach.
> 

Agree Krzysztof. I'll use the tach-ch property from the fan-common.yaml 
to solve my case. So I will not need to define a new vendor property as 
"maxim,pwmout-pin-as-tach-input". I'll drop this [Path 3/3] in the patch 
series v3.


> Best regards,
> Krzysztof
> 


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