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

[Arpit Saini]

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@xxxxxxxxxxxxxxxx>
> > >
> > > 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@xxxxxxxxxxxxxxxx>
> > > ---
> > >   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