Re: [PATCH V15 2/4] dt-bindings: pwm: add IPQ6018 binding

[Kathiravan Thirumoorthy <quic_kathirav@quicinc.com>]

On 10/20/2023 8:44 PM, Rob Herring wrote:
> On Wed, Oct 18, 2023 at 3:46 PM Uwe Kleine-König
> <u.kleine-koenig@pengutronix.de> wrote:
>> Hello,
>>
>> On Thu, Oct 05, 2023 at 09:35:48PM +0530, Devi Priya wrote:
>>> DT binding for the PWM block in Qualcomm IPQ6018 SoC.
>>>
>>> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>> Co-developed-by: Baruch Siach <baruch.siach@siklu.com>
>>> Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
>>> Signed-off-by: Devi Priya <quic_devipriy@quicinc.com>
>>> ---
>>> v15:
>>>
>>>    No change
>>>
>>> v14:
>>>
>>>    Picked up the R-b tag
>>>
>>> v13:
>>>
>>>    Updated the file name to match the compatible
>>>
>>>    Sorted the properties and updated the order in the required field
>>>
>>>    Dropped the syscon node from examples
>>>
>>> v12:
>>>
>>>    Picked up the R-b tag
>>>
>>> v11:
>>>
>>>    No change
>>>
>>> v10:
>>>
>>>    No change
>>>
>>> v9:
>>>
>>>    Add 'ranges' property to example (Rob)
>>>
>>>    Drop label in example (Rob)
>>>
>>> v8:
>>>
>>>    Add size cell to 'reg' (Rob)
>>>
>>> v7:
>>>
>>>    Use 'reg' instead of 'offset' (Rob)
>>>
>>>    Drop 'clock-names' and 'assigned-clock*' (Bjorn)
>>>
>>>    Use single cell address/size in example node (Bjorn)
>>>
>>>    Move '#pwm-cells' lower in example node (Bjorn)
>>>
>>>    List 'reg' as required
>>>
>>> v6:
>>>
>>>    Device node is child of TCSR; remove phandle (Rob Herring)
>>>
>>>    Add assigned-clocks/assigned-clock-rates (Uwe Kleine-König)
>>>
>>> v5: Use qcom,pwm-regs for phandle instead of direct regs (Bjorn
>>>      Andersson, Kathiravan T)
>>>
>>> v4: Update the binding example node as well (Rob Herring's bot)
>>>
>>> v3: s/qcom,pwm-ipq6018/qcom,ipq6018-pwm/ (Rob Herring)
>>>
>>> v2: Make #pwm-cells const (Rob Herring)
>>>
>>>   .../bindings/pwm/qcom,ipq6018-pwm.yaml        | 45 +++++++++++++++++++
>>>   1 file changed, 45 insertions(+)
>>>   create mode 100644 Documentation/devicetree/bindings/pwm/qcom,ipq6018-pwm.yaml
>>>
>>> diff --git a/Documentation/devicetree/bindings/pwm/qcom,ipq6018-pwm.yaml b/Documentation/devicetree/bindings/pwm/qcom,ipq6018-pwm.yaml
>>> new file mode 100644
>>> index 000000000000..6d0d7ed271f7
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/pwm/qcom,ipq6018-pwm.yaml
>>> @@ -0,0 +1,45 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/pwm/qcom,ipq6018-pwm.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: Qualcomm IPQ6018 PWM controller
>>> +
>>> +maintainers:
>>> +  - Baruch Siach <baruch@tkos.co.il>
>> Not being very fluent in dt and binding yaml I wonder if adding
>>
>>          allOf:
>>            - $ref: pwm.yaml#
>>
>> would be beneficial?!
> Not really because the only thing you pick up is #pwm-cells, but
> that's still needed here since that varies by binding. A reference
> generally becomes useful when there are child nodes (e.g. a bus
> binding) or multiple properties.
>
>>> +properties:
>>> +  compatible:
>>> +    const: qcom,ipq6018-pwm
>>> +
>>> +  reg:
>>> +    description: Offset of PWM register in the TCSR block.
>>> +    maxItems: 1
>>> +
>>> +  clocks:
>>> +    maxItems: 1
>>> +
>>> +  "#pwm-cells":
>>> +    const: 2
>> The driver only supports normal polarity. Is this a shortcoming of the
>> driver, or is the hardware incapable to do that, too?
>>
>> If it's only the former I'd want #pwm-cells = <3> here. For ease of use
>> I'd not oppose if you pick #pwm-cells = <3> even if the hardware can
>> only do normal polarity.
> Devi, Can we get an answer here soon.


Rob, Devi is on vacation for couple of weeks. I don't have much idea on 
this as of now, how can I help here, if needed?


>
> The MFD part has been applied and it references this schema causing
> warnings. So this needs to land or MFD schema reverted.
>
> Rob