Re: [PATCH v4 1/2] Add DT bindings YAML schema for PWM fan controller of LGM SoC

[Tanwar, Rahul]

Hi Rob,

On 14/7/2020 12:46 am, Rob Herring wrote:
> On Tue, Jun 30, 2020 at 03:55:31PM +0800, Rahul Tanwar wrote:
>> Intel's LGM(Lightning Mountain) SoC contains a PWM fan controller
>> which is only used to control the fan attached to the system. This
>> PWM controller does not have any other consumer other than fan.
>> Add DT bindings documentation for this PWM fan controller.
>>
>> Signed-off-by: Rahul Tanwar <rahul.tanwar@xxxxxxxxxxxxxxx>
>> ---
>>  .../devicetree/bindings/pwm/intel,lgm-pwm.yaml     | 50 ++++++++++++++++++++++
>>  1 file changed, 50 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml b/Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml
>> new file mode 100644
>> index 000000000000..120bf3d85a24
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml
>> @@ -0,0 +1,50 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/pwm/intel,lgm-pwm.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: LGM SoC PWM fan controller
>> +
>> +maintainers:
>> +  - Rahul Tanwar <rahul.tanwar@xxxxxxxxx>
>> +
>> +properties:
>> +  compatible:
>> +    const: intel,lgm-pwm
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    maxItems: 1
>> +
>> +  resets:
>> +    maxItems: 1
>> +
>> +  intel,fan-wire:
>> +    $ref: '/schemas/types.yaml#/definitions/uint32'
>> +    description: Specifies fan mode. Default when unspecified is 2.
>> +
>> +  intel,max-rpm:
>> +    $ref: '/schemas/types.yaml#/definitions/uint32'
>> +    description:
>> +      Specifies maximum RPM of fan attached to the system.
>> +      Default when unspecified is 4000.
> These are properties of the fan, not the PWM. And probably if you 
> need these properties then others would too, so they should be 
> common. Look at the pwm-fan.txt binding.

I checked pwm-fan.txt. I don't find any common property which matches
our fan properties of fan wire mode & max-rpm. Are you suggesting to
add these properties additionally in pwm-fan.txt as new common properties
and then use newly added generic name in our driver?

Also, we have a dedicated PWM fan controller. So do you think this driver
belongs to drivers/hwmon instead of drivers/pwm? Thanks.

Regards,
RahulÂ