Re: [PATCH v2 03/11] dt-bindings: arm: mediatek: add 'mediatek,pn_swap' property

[Krzysztof Kozlowski]

On 07/02/2023 19:00, Daniel Golle wrote:
> Hi Krzysztof,
> 
> On Tue, Feb 07, 2023 at 06:38:23PM +0100, Krzysztof Kozlowski wrote:
>> On 07/02/2023 15:19, Daniel Golle wrote:
>>> Add documentation for the newly introduced 'mediatek,pn_swap' property
>>> to mediatek,sgmiisys.txt.
>>>
>>
>> Please use scripts/get_maintainers.pl to get a list of necessary people
>> and lists to CC.  It might happen, that command when run on an older
>> kernel, gives you outdated entries.  Therefore please be sure you base
>> your patches on recent Linux kernel.
>>
>>> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
>>> ---
>>>  .../devicetree/bindings/arm/mediatek/mediatek,sgmiisys.txt    | 4 ++++
>>>  1 file changed, 4 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,sgmiisys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,sgmiisys.txt
>>> index d2c24c277514..b38dd0fde21d 100644
>>> --- a/Documentation/devicetree/bindings/arm/mediatek/mediatek,sgmiisys.txt
>>> +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,sgmiisys.txt
>>> @@ -14,6 +14,10 @@ Required Properties:
>>>  	- "mediatek,mt7986-sgmiisys_1", "syscon"
>>>  - #clock-cells: Must be 1
>>>  
>>> +Optional Properties:
>>> +
>>> +- mediatek,pn_swap: Invert polarity of the SGMII data lanes.
>>
>> No:
>> 1. No new properties for TXT bindings,
> 
> So I'll have to convert the bindings to YAML, right?

Yes, please.

> 
>> 2. Underscore is not allowed.
> 
> Ack, will change the name of the property.
> 
>> 3. Does not look like property of this node. This is a clock controller
>> or system controller, not SGMII/phy etc.
> 
> The register range referred to by this node *does* represent also an
> SGMII phy. These sgmiisys nodes also carry the 'syscon' compatible, and
> are referenced in the node of the Ethernet core, and then used by
> drivers/net/ethernet/mediatek/mtk_sgmii.c using syscon_node_to_regmap.
> (This is the current situation already, and not related to the patchset
> now adding only a new property to support hardware which needs that)

Just because a register is located in syscon block, does not mean that
SGMII configuration is a property of this device.

> 
> So: Should I introduce a new binding for the same compatible strings
> related to the SGMII PHY features? Or is it fine in this case to add
> this property to the existing binding?

The user of syscon should configure it. I don't think you need new
binding. You just have to update the user of this syscon.

Best regards,
Krzysztof