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 6/29/2026 4:24 PM, Arpit Saini wrote:
> 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.
>
In LCD Display Bias driver , it takes vin from vph_pwr along with LCD 
Bias enable (GPIO 151 controlled supply) and it outputs two signals 
vreg_disp_p as (+5.5v)

and vreg_disp_n as (-5.5v). I will update the dts as per this.

Thanks

Arpit


>>> +
>>> +        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
>>>