[PATCH v3 4/5] dt-bindings: display/msm: add stream pixel clock bindings for MST

[Dmitry Baryshkov]

On Thu, Jul 17, 2025 at 04:28:46PM -0700, Jessica Zhang wrote:
> From: Abhinav Kumar <quic_abhinavk at quicinc.com>
> 
> On some chipsets such as qcom,sa8775p-dp, qcom,sm8650-dp and some more,
> the display port controller can support more than one pixel stream
> (multi-stream transport).
> 
> These chipsets can support up to 4 stream pixel clocks for display port
> controller. To support MST on these platforms, add the appropriate
> stream pixel clock bindings
> 
> 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.
> 
> Note: On chipsets that do support MST, the number of streams supported
> can vary between controllers. For example, SA8775P supports 4 MST
> streams on mdss_dp0 but only 2 streams on mdss_dp1.
> 
> In addition, many chipsets depend on the "sm8350-dp" compatibility
> string but not all (ex. SM6350) support MST. Because of these reasons,
> the min/maxItem for MST-supported platforms is a range of 5-8.
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> Signed-off-by: Jessica Zhang <jessica.zhang at oss.qualcomm.com>
> ---
>  .../bindings/display/msm/dp-controller.yaml        | 36 +++++++++++++++++++++-
>  .../bindings/display/msm/qcom,sa8775p-mdss.yaml    | 10 ++++--
>  .../bindings/display/msm/qcom,sar2130p-mdss.yaml   |  6 ++--
>  .../bindings/display/msm/qcom,sc7280-mdss.yaml     |  6 ++--
>  .../bindings/display/msm/qcom,sm8750-mdss.yaml     |  6 ++--
>  .../bindings/display/msm/qcom,x1e80100-mdss.yaml   |  6 ++--
>  6 files changed, 59 insertions(+), 11 deletions(-)

I've cross-checked. We need to stop declaring SM6350 as compatible with
SM8350, it doesn't provide MST support (and so there will be a need for
a driver update too). Other than that, please document DP MST on SDM845.
With those changes in place, I think, all platforms will be covered.

-- 
With best wishes
Dmitry