[PATCH 3/4] dt-bindings: display/msm: add stream 1 pixel clock binding

[Abhinav Kumar]

On 4/23/2025 7:23 AM, Dmitry Baryshkov wrote:
> On Tue, Apr 22, 2025 at 07:46:57PM -0700, Abhinav Kumar wrote:
>>
>>
>> On 12/3/2024 5:43 AM, Dmitry Baryshkov wrote:
>>> On Mon, Dec 02, 2024 at 07:31:41PM -0800, Abhinav Kumar wrote:
>>>> On some chipsets the display port controller can support more
>>>> than one pixel stream (multi-stream transport). To support MST
>>>> on such chipsets, add the binding for stream 1 pixel clock for
>>>> display port controller. Since this mode is not supported on all
>>>> chipsets, add exception rules and min/max items to clearly mark
>>>> which chipsets support only SST mode (single stream) and which ones
>>>> support MST.
>>>>
>>>> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
>>>> ---
>>>>    .../bindings/display/msm/dp-controller.yaml        | 32 ++++++++++++++++++++++
>>>>    .../bindings/display/msm/qcom,sa8775p-mdss.yaml    |  9 ++++--
>>>>    2 files changed, 38 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/display/msm/dp-controller.yaml b/Documentation/devicetree/bindings/display/msm/dp-controller.yaml
>>>> index 9fe2bf0484d8..650d19e58277 100644
>>>> --- a/Documentation/devicetree/bindings/display/msm/dp-controller.yaml
>>>> +++ b/Documentation/devicetree/bindings/display/msm/dp-controller.yaml
>>>> @@ -50,30 +50,38 @@ properties:
>>>>        maxItems: 1
>>>>      clocks:
>>>> +    minItems: 5
>>>>        items:
>>>>          - description: AHB clock to enable register access
>>>>          - description: Display Port AUX clock
>>>>          - description: Display Port Link clock
>>>>          - description: Link interface clock between DP and PHY
>>>>          - description: Display Port stream 0 Pixel clock
>>>> +      - description: Display Port stream 1 Pixel clock
>>>>      clock-names:
>>>> +    minItems: 5
>>>>        items:
>>>>          - const: core_iface
>>>>          - const: core_aux
>>>>          - const: ctrl_link
>>>>          - const: ctrl_link_iface
>>>>          - const: stream_pixel
>>>> +      - const: stream_1_pixel
>>>>      assigned-clocks:
>>>> +    minItems: 2
>>>>        items:
>>>>          - description: link clock source
>>>>          - description: stream 0 pixel clock source
>>>> +      - description: stream 1 pixel clock source
>>>>      assigned-clock-parents:
>>>> +    minItems: 2
>>>>        items:
>>>>          - description: Link clock PLL output provided by PHY block
>>>>          - description: Stream 0 pixel clock PLL output provided by PHY block
>>>> +      - description: Stream 1 pixel clock PLL output provided by PHY block
>>>>      phys:
>>>>        maxItems: 1
>>>> @@ -175,6 +183,30 @@ allOf:
>>>>          required:
>>>>            - "#sound-dai-cells"
>>>> +  - if:
>>>> +      properties:
>>>> +        compatible:
>>>> +          contains:
>>>> +            enum:
>>>> +              - qcom,sa8775p-dp
>>>
>>> Why do you need an extra platform conditional?
>>>
>>
>> I expect this list to grow and also there can be chipsets which support 4
>> streams as well, so an extra platform conditional was needed.
> 
> Ack
> 
>>
>>>> +
>>>> +    then:
>>>> +      properties:
>>>> +        clocks:
>>>> +          maxItems: 6
>>>> +        clock-names:
>>>> +          items:
>>>> +            - const: core_iface
>>>> +            - const: core_aux
>>>> +            - const: ctrl_link
>>>> +            - const: ctrl_link_iface
>>>> +            - const: stream_pixel
>>>> +            - const: stream_1_pixel
> 
> You don't need to ducplicate the list. Just specify min/maxItems.
> 

Ack

>>>> +        assigned-clocks:
>>>> +          maxItems: 3
>>>> +        assigned-clock-parents:
>>>> +          maxItems: 3
>>>> +
>>>>    additionalProperties: false
>>>>    examples:
>>>> diff --git a/Documentation/devicetree/bindings/display/msm/qcom,sa8775p-mdss.yaml b/Documentation/devicetree/bindings/display/msm/qcom,sa8775p-mdss.yaml
>>>> index 58f8a01f29c7..7f10e6ad8f63 100644
>>>> --- a/Documentation/devicetree/bindings/display/msm/qcom,sa8775p-mdss.yaml
>>>> +++ b/Documentation/devicetree/bindings/display/msm/qcom,sa8775p-mdss.yaml
>>>> @@ -177,16 +177,19 @@ examples:
>>>>                         <&dispcc_dptx0_aux_clk>,
>>>>                         <&dispcc_dptx0_link_clk>,
>>>>                         <&dispcc_dptx0_link_intf_clk>,
>>>> -                     <&dispcc_dptx0_pixel0_clk>;
>>>> +                     <&dispcc_dptx0_pixel0_clk>,
>>>> +                     <&dispcc_dptx0_pixel1_clk>;
>>>>                clock-names = "core_iface",
>>>>                              "core_aux",
>>>>                              "ctrl_link",
>>>>                              "ctrl_link_iface",
>>>> -                          "stream_pixel";
>>>> +                          "stream_pixel",
>>>> +                          "stream_1_pixel";
>>>>                assigned-clocks = <&dispcc_mdss_dptx0_link_clk_src>,
>>>> +                              <&dispcc_mdss_dptx0_pixel1_clk_src>,
>>>>                                  <&dispcc_mdss_dptx0_pixel0_clk_src>;
>>>> -            assigned-clock-parents = <&mdss0_edp_phy 0>, <&mdss0_edp_phy 1>;
>>>> +            assigned-clock-parents = <&mdss0_edp_phy 0>, <&mdss0_edp_phy 1>, <&mdss0_edp_phy 1>;
>>>>                phys = <&mdss0_edp_phy>;
>>>>                phy-names = "dp";
>>>>
>>>> -- 
>>>> 2.34.1
>>>>
>>>
>>
>