Re: [PATCH 2/5] arm64: dts: qcom: shikra-cqm-evk: Enable display and add ili7807s panel

[Arpit Saini <arpit.saini@oss.qualcomm.com>]

Hi Dmitry,

On 6/28/2026 6:00 PM, Dmitry Baryshkov wrote:
> On Sat, Jun 27, 2026 at 03:31:36PM +0530, Nabige Aala wrote:
>> From: Arpit Saini <arpit.saini@oss.qualcomm.com>
>>
>> Enable the Shikra MDSS display subsystem on the Shikra CQM EVK
>> board and add the DLC0697 MIPI DSI display panel node.
>> Pin pm4125_l5 to 1.232V with regulator-allow-set-load
>> for DSI PHY PLL stability.
>>
>> Signed-off-by: Arpit Saini <arpit.saini@oss.qualcomm.com>
>> ---
>>   arch/arm64/boot/dts/qcom/shikra-cqm-evk.dts | 104 ++++++++++++++++++++++++++++
>>   1 file changed, 104 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/shikra-cqm-evk.dts b/arch/arm64/boot/dts/qcom/shikra-cqm-evk.dts
>> index 683b5245923b..c9ea093cd8ca 100644
>> --- a/arch/arm64/boot/dts/qcom/shikra-cqm-evk.dts
>> +++ b/arch/arm64/boot/dts/qcom/shikra-cqm-evk.dts
>> @@ -23,6 +23,18 @@ chosen {
>>   		stdout-path = "serial0:115200n8";
>>   	};
>>   
>> +	lcd_bias: regulator-lcd-bias {
>> +		compatible = "regulator-fixed";
>> +		regulator-name = "lcd_bias";
>> +		regulator-min-microvolt = <3300000>;
>> +		regulator-max-microvolt = <3300000>;
>> +		vin-supply = <&pm4125_l17>;
>> +		gpio = <&tlmm 151 GPIO_ACTIVE_HIGH>;
>> +		enable-active-high;
>> +		pinctrl-0 = <&lcd_bias_en>;
>> +		pinctrl-names = "default";
>> +	};
>> +
>>   	wcn3988-pmu {
>>   		compatible = "qcom,wcn3988-pmu";
>>   
>> @@ -60,6 +72,52 @@ vreg_pmu_ch1: ldo4 {
>>   	};
>>   };
>>   
>> +&mdss {
>> +	status = "okay";
>> +};
>> +
>> +&mdss_dsi0 {
>> +	vdda-supply = <&pm4125_l5>;
>> +	status = "okay";
> Empty lines before the status property, please.

Ack, will update.


>> +
>> +	panel@0 {
>> +		compatible = "dlc,dlc0697", "ilitek,ili7807s";
>> +		reg = <0>;
>> +
>> +		reset-gpios = <&tlmm 3 GPIO_ACTIVE_LOW>;
>> +
>> +		vddi-supply = <&pm4125_l15>;
>> +		avdd-supply = <&lcd_bias>;
>> +		avee-supply = <&lcd_bias>;
> AVEE is typically the negative / ground supply. How can it be supplied
> by the same regulator as AVDD?

Ack , I will update this using two seperate regulator-fixed nodes, 
vreg_disp_p and vreg_disp_n

as defined in schematics.

Thanks for pointing out.

>> +
>> +		pinctrl-0 = <&panel_bl_en &panel_rst_n &panel_te_pin>;
>> +		pinctrl-1 = <&panel_bl_en_suspend &panel_rst_n_suspend>;
>> +		pinctrl-names = "default", "sleep";
>> +
>> +		port {
>> +			panel_in: endpoint {
>> +				remote-endpoint = <&mdss_dsi0_out>;
>> +			};
>> +		};
>> +	};
>> +};
>> +
>> +&mdss_dsi0_out {
>> +	remote-endpoint = <&panel_in>;
>> +	data-lanes = <0 1 2 3>;
>> +};
>> +
>> +&mdss_dsi0_phy {
>> +	status = "okay";
>> +};
>> +
>> +&pm4125_l5 {
>> +	/* DSI VDDA - must be at NOM voltage for PHY PLL lock */
>> +	regulator-min-microvolt = <1232000>;
>> +	regulator-max-microvolt = <1232000>;
>> +	regulator-allow-set-load;
>> +};
>> +
>>   &remoteproc_cdsp {
>>   	firmware-name = "qcom/shikra/cdsp.mbn";
>>   
>> @@ -116,3 +174,49 @@ &wifi {
>>   
>>   	status = "okay";
>>   };
>> +
>> +&tlmm {
>> +	lcd_bias_en: lcd-bias-en-state {
>> +		pins = "gpio151";
>> +		function = "gpio";
>> +		drive-strength = <2>;
>> +		bias-disable;
>> +	};
>> +
>> +	panel_bl_en: panel-bl-en-state {
>> +		pins = "gpio91";
>> +		function = "gpio";
>> +		drive-strength = <2>;
>> +		bias-disable;
>> +		output-high;
> I think, recent recommendation is to sort these entries by the pin
> number.

Ack, will update.


>> +	};
>> +
>> +	panel_bl_en_suspend: panel-bl-en-suspend-state {
>> +		pins = "gpio91";
>> +		function = "gpio";
>> +		drive-strength = <2>;
>> +		bias-pull-down;
>> +		output-low;
>> +	};
>> +
>> +	panel_rst_n: panel-rst-n-state {
>> +		pins = "gpio3";
>> +		function = "gpio";
>> +		drive-strength = <8>;
>> +		bias-disable;
>> +	};
>> +
>> +	panel_rst_n_suspend: panel-rst-n-suspend-state {
>> +		pins = "gpio3";
>> +		function = "gpio";
>> +		drive-strength = <2>;
>> +		bias-pull-down;
>> +	};
>> +
>> +	panel_te_pin: panel-te-pin-state {
>> +		pins = "gpio86";
>> +		function = "mdp_vsync_p";
>> +		drive-strength = <2>;
>> +		bias-pull-down;
>> +	};
>> +};
>>
>> -- 
>> 2.34.1
>>