[PATCH 2/3] dt-bindings: phy: rockchip-inno-csi-dphy: add rockchip,clk-lane-phase property

[Gerald Loacker]

Hi Conor,

Am 17.06.2026 um 17:51 schrieb Conor Dooley:
> On Wed, Jun 17, 2026 at 02:23:14PM +0200, Gerald Loacker wrote:
>> Add support for the optional rockchip,clk-lane-phase device tree property
>> to allow board-specific tuning of the clock lane sampling phase for
>> improved signal integrity across supported data rates.
>>
>> Signed-off-by: Gerald Loacker <gerald.loacker at wolfvision.net>
>> ---
>>  Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
>> index 03950b3cad08c..0d824d1511bc0 100644
>> --- a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
>> +++ b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
>> @@ -56,6 +56,13 @@ properties:
>>      description:
>>        Some additional phy settings are access through GRF regs.
>>  
>> +  rockchip,clk-lane-phase:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    minimum: 0
>> +    maximum: 7
>> +    description:
>> +      Clock lane sampling phase in 40 ps steps. The hardware default is 3.
> 
> Can this instead become rockchip,clk-lane-phase-ps and be listed in the
> actual unit?
> With the -ps suffix, you can then drop the $ref.
> The default should be listed as "default: 3" (or default: 120)
> 
> pw-bot: changes-requested
> 

Thanks for the suggestion.

The phase setting is a hardware tap index (0–7) selecting a delay line
position. The datasheet mentions “about 40 ps” per step, but this is not
a calibrated or guaranteed value and may vary with PVT.

Because of that, I’d prefer to keep the property as an index and
document the approximate delay in the description:

Clock lane sampling phase selection (hardware tap index 0–7). Each step
corresponds to an approximately 40 ps delay as described in the hardware
specification.

This matches the hardware model more closely. Happy to adjust if needed.

>> +
>>  required:
>>    - compatible
>>    - reg
>>
>> -- 
>> 2.34.1
>>