[PATCH 2/5] arm64: dts: qcom: sm8250: Add DisplayPort device node

[Dmitry Baryshkov]

On 12/07/2023 00:34, Konrad Dybcio wrote:
> On 9.07.2023 06:19, Dmitry Baryshkov wrote:
>> Declare the displayport controller present on the Qualcomm SM8250 SoC.
>>
>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>> ---
> [...]
> 
>> +				dp_opp_table: opp-table {
>> +					compatible = "operating-points-v2";
>> +
>> +					opp-160000000 {
>> +						opp-hz = /bits/ 64 <160000000>;
>> +						required-opps = <&rpmhpd_opp_low_svs>;
> 19.2 MHz, VDD_MIN

I don't think so, the lowest working point is 162 MHz for RBR. 19.2 is 
just just artificial. I'll check, maybe it would be better to drop this 
completely.

> 
>> +					};
>> +
>> +					opp-270000000 {
>> +						opp-hz = /bits/ 64 <270000000>;
>> +						required-opps = <&rpmhpd_opp_svs>;
> 270 MHz, LOW_SVS

Ack. Which probably means that we should fix all existing DP opp tables. 
They all should be using low_svs here.

>> +					};
>> +
>> +					opp-540000000 {
>> +						opp-hz = /bits/ 64 <540000000>;
>> +						required-opps = <&rpmhpd_opp_svs_l1>;
> 540 MHz, SVS_L1 (ok)
>> +					};
>> +
>> +					opp-810000000 {
>> +						opp-hz = /bits/ 64 <810000000>;
>> +						required-opps = <&rpmhpd_opp_nom>;
> 810 MHz, NOM (also ok)
> 
> (but then - there's qcom,max-pclk-frequency-khz = <675000>;)
> 
> also, what's up with the PIXEL1 clocks etc.?
> they are capped at the aforementioned 675 Mhz but I have no idea
> what they're for

I think PIXEL1 is used for DP MST.

> 
> Konrad
>> +					};
>> +				};
>> +			};
>> +
>>   			mdss_dsi0: dsi at ae94000 {
>>   				compatible = "qcom,sm8250-dsi-ctrl",
>>   					     "qcom,mdss-dsi-ctrl";

-- 
With best wishes
Dmitry